Johns Hopkins Health Alerts Current Issue

What Should You Do About Bone Spurs?

Mon, 19 Oct 2009 06:00:00 CDT

Bone spurs -- also called osteophytes -- are benign, bony bumps that usually form on the joints. Most are harmless and never detected. But if they limit your movement or cause pain, treatment is available. Here’s what you should know.

To some extent, bone spurs are just a normal part of aging; your body may produce them to compensate for gradual bone loss that occurs overtime. Bone spurs may also be a result of arthritis or other bone diseases. As cartilage in the joints wears away in arthritis patients, bones begin to rub directly against each other and bone spurs develop. These bumps may protrude into surrounding tendons or break off and float in the space within joints, causing swelling or interfering with range of motion.

In the spine, bone spurs may lead to stenosis (narrowing of the spinal canal) and exert pressure on the nerves, causing muscle weakness, tingling, loss of coordination, or radiating pain in the buttocks, thighs, or shoulders. Bone spurs in the spine's cervical region can push into the throat, making it difficult to swallow or breathe. Symptoms like these may indicate diffuse idiopathic skeletal hyperostosis (DISH), a condition characterized by multiple bone spurs and ossified ligaments, usually in the spine (though DISH can affect other areas of the body).

If you are experiencing symptoms, your doctor will examine you and possibly order x-rays or other imaging tests. The best way to treat a bone spur is by addressing the underlying cause. In addition to arthritis and other medical conditions like DISH, excess weight, bad posture, old athletic injuries, or even shoes that don't fit well may be to blame.

Conservative therapy usually involves rest, icing, stretching, and non-steroidal anti-inflammatory drugs (NSAIDs ). Also, even though your symptoms may seem to worsen with movement, targeted physical therapy exercises can restore range of motion in the joints and promote good posture (which reduces pressure on nerves). For temporary relief of serious pain, you may be given cortisone shots.

Surgical removal is an option for more severe symptoms, particularly if you already require surgery for arthritis. Some people choose to have bone spurs taken out for cosmetic reasons, especially when the hands are affected. Removal can be performed through open or laparoscopic procedures.

6 Simple Stretches for Pain-Free Travel

Fri, 23 Oct 2009 06:00:00 CDT

Don't let back or neck pain cramp your travel fun. Experts who treat back pain recommend that you stretch regularly while you’re in flight or when you take a driving break. Stretching can help relax tense muscles and overly tight ligaments in the back and neck.

Traveling by car or plane can be a pain in the neck, literally, as well as a pain in the back. Sitting for prolonged periods adds strain to the structures of the lower back and neck, and poor posture while sitting puts even more stress on your spine. Regular travel with back or neck pain can be a challenge, but you can take measures to reduce or avoid pain and discomfort while on the road or in the air.

Here are six simple, yet effective stretches to help you can do anywhere, without a lot of fancy equipment:

Neck and shoulder stretches :

To loosen your neck, rotate your head to the left and maintain this position for about five seconds. Turn your head forward again; then turn to the right and hold for five seconds. Repeat five times.

To loosen your shoulders and neck, shrug your shoulders up while holding your arms at your sides. Stay in this position for about five seconds, then return to a resting position. Repeat five times.

Back stretches:

Begin in an upright, seated position and gradually lower your torso toward your knees. Let your arms drop down and then wrap them around your thighs. Hold this position for about 20 seconds while breathing deeply, then return to your normal, seated position. Repeat five times.

While standing, put your hands on your lower back and slowly stretch backward from the waist. Hold for 10 seconds, then relax and straighten up. Repeat five times.

Place your hands on your hips and bend to the left. Maintain this position for five seconds. Return to an upright position, then bend to the right and hold for five seconds. Repeat five times.

Leg stretch:

While sitting, keep the balls of your feet on the floor and raise your heels. Hold for 10 seconds. Lower your heels back down, and repeat 10 times. Although this is really a calf stretch exercise, you’ll feel the stretch all the way up into your lower back.

Clinical Trial Terminology Explained

Tue, 20 Oct 2009 06:00:00 CDT

The National Cancer Institute estimates that between 5% and 8% of cancer patients participate in clinical trials. Why is the number so low? Part of the problem is that many patients believe that all clinical trials include a placebo (an inactive treatment with no known therapeutic value) and treat participants like "guinea pigs" -- neither of which is true. To help clear up the confusion, this Health Alert explains clinical trial terminology, including randomization, placebo, and blinding.

Clinical trials are studies conducted in humans to identify new methods of screening, preventing, diagnosing, or treating a disease or to compare innovative approaches to treatment with the standard treatments currently in use. Before researchers conduct a clinical trial, the treatment has usually gone through extensive laboratory and animal testing. Once researchers have good evidence from these preclinical studies that a treatment might work in people, they can request approval from the U.S. Food and Drug Administration to test it in humans.

When considering clinical trials, you'll be confronted with a host of terms that may be unfamiliar. For example:

Randomization. If you enter a randomized clinical trial, you will be assigned by chance to a control group or a treatment group. If you are assigned to the control group, you will receive the standard treatment or procedure -- the one you would receive if you were not participating in the study. If you are assigned to the treatment group, you will receive the experimental treatment or procedure.

Placebo group. In some phase II and III clinical trials, participants are assigned to a placebo group instead of a control group and receive an inactive pill or sham treatment that has no effect on the disease. Placebos are never used when a patient could benefit from a known effective treatment; thus, most cancer treatment trials do not have a placebo group. However, a placebo group may be used if there is no standard therapy with which to compare the experimental treatment. A placebo is also sometimes used in studies where everyone receives the standard treatment but half also receive an experimental treatment and half a placebo.

Blinding. Some randomized clinical trials are "blinded," meaning you won't know whether you are getting the treatment being studied or the standard treatment until the trial is over. In a "double-blinded" clinical trial, neither you nor the investigators will know which treatment you are getting until the trial has ended. This practice minimizes the chances that a treatment seems to work only because of the expectations or biases of those involved in the study. Blinding is often done when a placebo is included in one part of the clinical trial.

What's Minor About Minor Depression?

Wed, 21 Oct 2009 06:00:00 CDT

A reader from Landmark, SC asks: My husband's primary care physician told him he has "minor depression." I understand what major depression is, but what is minor depression? Johns Hopkins answers.

Minor depression is not a formal psychiatric diagnosis. That being said, the term may indicate several possibilities. Minor depression may be used to describe a depressive episode that does not meet the formal diagnostic criteria for major depressive disorder.

Major depressive disorder consists of at least one episode of major depression, which by definition must entail at least five out of nine of the following signs and symptoms for a minimum of two weeks: depressed mood, diminished interest in all, guilty feelings, low energy, poor concentration, sleep disturbances, appetite disturbances, psychomotor agitation or retardation, and suicidality.

In addition, to qualify as a major depressive episode, one of the five criteria must be depressed mood. Lastly, there must be impairment of functioning in social or occupational spheres. If all of these criteria are not met, a patient might be described as having a "minor depression."

Minor depression might also be used to classify an episode of depression in which the signs and symptoms are present but not very severe. For example, your husband may have mild symptoms of sleep, appetite, and concentration disturbance that result in taking longer to complete tasks at work. However, if he is still able to get his work done in a reasonable amount of time and the other aspects of depression are mild, it would be difficult to give a diagnosis of major depressive disorder.

Minor depression could also be meant to describe dysthymia, which consists of a depressed mood for more days than not over a two-year time period. In addition, the individual should have two additional symptoms of depression, such as hopelessness, poor self esteem, and sleep, appetite, or concentration disturbance, to receive a diagnosis of dysthymia.

In summary, mild depression is not a formal diagnosis, but may include a subthreshold major depressive episode or chronic depressive symptoms. Depending on the particulars of the case, psychotherapy and possibly pharmacotherapy may be beneficial. Evaluation by a psychiatrist would be helpful in guiding your husband's treatment.

Putting Portion Control to the Test

Thu, 01 Oct 2009 06:00:00 CDT

Eat fewer calories than you burn and you will lose weight. Sounds simple, but for many people – especially those with diabetes – it is a difficult challenge. Now research in the Archives of Internal Medicine suggests that portion control can help.

Everyone knows that cutting calories and losing weight require you to reduce how much you eat -- which means downsizing your portions. A recent study shows that controlling portions may be particularly helpful for individuals with diabetes who take insulin and often find it difficult to lose weight.

In a study from the Archives of Internal Medicine, Canadian researchers randomized 130 obese participants with type 2 diabetes, including 55 people taking insulin, either to use a portion-control plate for meals or to obtain usual care in the form of dietary teaching. The plate allowed for an 800-calorie meal for men with diabetes and a 650-calorie meal for women with diabetes.

After six months, individuals with diabetes who controlled portions lost an average of 1.8% of their body weight compared with those in usual care who lost an average of 0.1%. Among those taking insulin, those in the intervention group lost 2.6% of their body weight compared with 0.1% in the control group.

More portion controllers lost a significant amount of weight; almost 17% lost at least 5% of their body weight while only 4.6% of controls did. And 26% of the intervention group were able to decrease their use of glucose-lowering medications compared with 11% in the usual-care group.

Nutritionists point out that special plates and bowls, which are commercially available, can be helpful in controlling calories since people's idea of an average portion size has increased radically over the years. Studies have shown that the more that people have on their plate, the more they will eat -- so serving smaller meals on smaller dishes may help you cut back.

Should You Try a Gluten-Free Diet?

Mon, 26 Oct 2009 06:00:00 CDT

People with celiac disease are sensitive to gluten, a component of wheat and other grains. No medication or surgical procedure can cure celiac disease. The only way to treat it is to adopt a completely gluten-free diet: avoiding all food and drink containing wheat, barley, rye, and other grains. But what if you don’t have celiac? Is a gluten-free diet good for your health?

As diagnosis and awareness of celiac disease have increased, a wide variety of gluten-free foods have hit store shelves. While these products are essential for people with celiac disease and gluten sensitivity, their benefit for others is less definitive.

Celiac disease causes intestinal damage that's visible on a biopsy. Gluten sensitivity, meanwhile, may cause some of celiac disease's gastrointestinal (GI) symptoms -- diarrhea, gas, bloating, vomiting, and constipation -- but not intestinal damage. There's no evidence that gluten sensitivity will one day turn into celiac disease, so avoiding gluten is more about reducing present symptoms than preventing future damage.

Gluten alone is not harmful to anyone without celiac disease, but it is present in many unhealthy foods. Refined carbohydrates can make you feel sluggish, but it's probably the spike in blood glucose levels and the lack of fiber -- not the gluten -- that's to blame.

If you have GI symptoms, see your doctor before adopting a gluten-free diet. You may need to be tested for celiac disease, and going gluten free beforehand can make intestinal damage less obvious on a biopsy.

For people without celiac disease or gluten sensitivity, a strict gluten-free diet probably isn't worth any potential health benefits: It can be deficient in some nutrients, such as B vitamins (particularly folic acid).

What Causes BPH?

Tue, 27 Oct 2009 06:00:00 CDT

If you experience a frequent urge to urinate, urinary incontinence, or intermittent urine flow, you may have an enlarged prostate or BPH – a common, non-cancerous condition affecting one in four men by age 55. What is BPH? Here is an explanation, in brief.

Although the cause of enlarged prostate hyperplasia (BPH) is not well understood, normal levels of testosterone and aging are essential for the development of the condition. Studies in dogs suggest that the female sex hormone estrogen may also play a role in BPH.

The word hyperplasia refers to any abnormal accumulation of cells that causes enlargement of a body part or organ. BPH occurs when an increase in the number of prostate cells produces discrete nodules in the prostate. The increase in nodules is due to a slowing of the normal rate of death of these cells, rather than to a heightened production.

Whether or not the resulting enlargement puts pressure on the urethra and increases resistance to urine flow depends on the location of the nodules. Although the transition zone accounts for only about 5 percent of the prostate mass, the nodules in men with BPH occur primarily in this region.

Because the transition zone directly envelops the urethra, excess tissue tends to obstruct urine flow. Contractions of the smooth muscle cells surrounding the nodules can also obstruct the urethra.

Consequently, some men with a very enlarged prostate may have no urethral obstruction, while others with mild enlargement may have marked symptoms because a nodule is located where it compresses the urethra, or because smooth muscles tighten. To compensate for urethral narrowing, the muscular wall of the bladder contracts more strongly to expel urine. These stronger contractions lead to a thickened bladder wall, which decreases the bladder's capacity to store urine.

Over time, the bladder holds smaller and smaller amounts of urine, resulting in a need to urinate more frequently. As the urethral obstruction worsens, the contractions can no longer empty the bladder completely. Urine retained in the bladder may then become infected or lead to the formation of bladder stones. Less often, the kidneys become damaged, either as a result of increased pressure on them from the overworked bladder or because an infection has spread from the bladder to the kidneys.

Pill Splitting Advice

Wed, 28 Oct 2009 06:00:00 CDT

Prescription medication is expensive, so many patients split their pills to save money. Is this a good idea? Here’s advice from Johns Hopkins.

Pill splitting is a good way to save on the cost of prescription medication, since a 200-mg dose typically costs the same as a 100-mg dose of a particular drug.

But it is essential to ask your doctor and pharmacist whether your medication can be split safely, because it is very easy to split pills unevenly. For people with certain medical conditions, like epilepsy and some heart problems, an inadequate dose can be dangerous. Correct dosage is also essential for hormone medications. Other medication that shouldn't be split:

Extended-release pills that deliver medication over time

Combination tablets that contain more than one medication

Pills coated to protect the stomach from irritation

Pills that crumble easily or are awkwardly shaped

Pills that are difficult to swallow because of bitter taste

Powder or gel capsules

That said, other medications can be split, like sildenafil (Viagra), certain blood pressure medications, many antidepressants, and most statins. Pills that are scored to make cutting easier indicate approval from the U.S. Food and Drug Administration to split the tablets.

Don't split pills with your hands or a knife -- this could lead to inaccurate doses. Buy a pill splitter at your local drugstore. Most cost $5-10; ask your pharmacist for a demonstration.

Flu shot a MUST for People with Heart Disease

Fri, 30 Oct 2009 06:00:00 CDT

Have you had your annual flu shot? Between 10% and 20% of people catch the flu each year, and a bad case can be deadly for individuals with coronary heart disease. Yet only one in three adults with cardiovascular disease get an annual flu shot. Read what the AHA advises.

People with heart disease are not only at higher risk for the flu than the general population but also more likely to have a severe case and to develop complications, such as viral or bacterial pneumonia. What's more, the flu can worsen coronary heart disease and trigger a heart attack.

No one knows for sure how the flu increases the risk of a heart attack. One possibility: Inflammation associated with the flu can trigger the rupture of unstable plaque, leading to the formation of a blood clot that could cause a heart attack.

Heart Benefits of the Flu Shot -- The strongest evidence for protection from a flu shot in people with heart disease comes from the Flu Vaccination in Acute Coronary Syndromes (FLUVACS) study. In that study, about 300 individuals who had been hospitalized for either a heart attack or a planned angioplasty were randomly assigned to receive a flu vaccine or remain unvaccinated. Over the next year, twice as many of the unvaccinated group (23%) died of heart disease, had a nonfatal heart attack, or developed severe ischemia (insufficient blood supply to the heart tissue), compared with those who were vaccinated (11%).

Bottom line advice: The American Heart Association (AHA) recommends a flu shot with the same enthusiasm as it does the control of cholesterol, blood pressure, and other modifiable risk factors for heart attacks. In a scientific advisory issued by the AHA and the American College of Cardiology heart doctors were asked to do something they may not normally do -- give their patients flu shots.

The Centers for Disease Control and Prevention also recommends an annual flu shot for individuals age 50 and older as well as anyone with a chronic health problem such as heart disease or diabetes. Besides getting a flu shot, two other simple measures -- frequent hand washing and, if possible, avoiding close contact with a flu sufferer -- can help reduce the risk of catching the flu.

Transcendental Meditation and Your Blood Pressure

Tue, 03 Nov 2009 06:00:00 CST

A reader with high blood pressure asks: Will relieving stress help control high blood pressure? Which stress reduction technique has the most evidence backing it up? Here’s the reply from Johns Hopkins.

In stressful situations, your body releases hormones like epinephrine that cause your blood pressure to rise and your heart rate to accelerate. Whether chronic stress contributes to high blood pressure is less clear. Still, reducing stress may help you follow other lifestyle recommendations and maintain other healthy habits.

Stress reduction techniques include exercising regularly; practicing relaxation techniques such as deep breathing, guided imagery, or meditation; lightening your work or personal schedule; and having a strong social network of friends and family. Some activities that people believe lower stress -- drinking too much alcohol and smoking -- actually increase blood pressure.

The effects of stress on blood pressure are controversial. Likewise, it is unclear if stress-reduction techniques, such as biofeedback, yoga, and tai chi, help lower blood pressure.

But one method of reducing stress called transcendental meditation (TM) has the most evidence. Developed more than 50 years ago, TM involves sitting quietly for 20-minute periods, twice a day, and repeating a one-syllable word called a mantra to relax the mind.

The effects of TM on blood pressure were recently evaluated in a meta-analysis published in the American Journal of Hypertension. When the researchers considered three high-quality, randomized, controlled trials of TM in people with high blood pressure, they found that this form of meditation reduced systolic blood pressure by 6 mm Hg and diastolic blood pressure by 3 mm Hg. TM likely lowers blood pressure because of its effects on the nervous system, slowing heart rate and reducing tension in the muscles.

If you are interested in trying TM, you can learn how to do it through books, audiotapes, and DVDs. You may also find a certified instructor giving classes in your area. Keep in mind, however, that TM is not a substitute for the lifestyle measures or medications proven to lower blood pressure. But trying it will cause you no harm.

True or False: Thunderstorms Trigger Asthma Attacks

Thu, 08 Oct 2009 06:00:00 CDT

For some asthma patients, the answer is “True.” Scientists in Atlanta report a surprising asthma trigger -- thunderstorms. They found that thunderstorms are associated with a 3% increase in emergency room visits for asthma.

The most likely explanations for the association are that pollen grains rupture in rainwater, releasing allergens, and that winds from thunderstorm downdrafts spread allergens, which may lead to an increased risk of asthma attacks.

The researchers used an emergency department (ED) visit database containing information on more than 10 million ED visits from 41 of 42 hospitals in Atlanta between 1993 and 2004. They looked at people who visited the ED for asthma and compared the zip codes in which they lived with rain and wind data for those areas. Of 215,832 asthma visits, 24,350 occurred on days following thunderstorms. Visits to the ED for asthma were highest when wind gusts were intermediate and high.

While a 3% increase in risk may seem modest, the researchers note, asthma is quite prevalent in Atlanta, and even a modest increase could have a significant public health impact. If you have asthma, pay attention to your breathing symptoms the next time there's a thunderstorm.

If you find that they trigger your asthma, you may want to stay inside during and after thunderstorms whenever possible.

Reported in THORAX (Volume 63, page 659).

Another Reason to Nap

Mon, 02 Nov 2009 06:00:00 CST

If you enjoy an afternoon nap, here’s good news. A study published in the Journal of Sleep Research suggests that napping may improve your memory. Here’s what the researchers found.

Although memory impairment is common as we age and usually is not a sign of a serious neurological disorder, it can be frustrating and socially embarrassing. The minor memory lapses that occur with age-associated memory impairment can’t be eliminated completely; however, a number of strategies can improve overall memory at any age.

For example, a good night’s sleep has been shown to boost your memory, and now a small study reported in the Journal of Sleep Research (Volume 17, page 3) suggests that even a short daytime nap can help, too.

German researchers conducted two experiments involving 26 university students ages 20 to 29. In the first experiment, the volunteers were asked to memorize 30 adjectives within two minutes and then to recall as many as possible after either a one-hour nap or one hour of waking activities. Each participant was tested in both the napping and waking conditions, and the experiments were repeated one week after the first testing sessions.

The results showed that the students performed significantly better after napping, and their performance was not affected by the time spent in slow-wave sleep (deep sleep). The second experiment tested participants for word recall after no nap, a long nap (35 minutes), and a short nap (six minutes).

Bottom line: The students performed the best after the long nap, but even the very brief nap significantly boosted memory processing compared with no nap at all. It may be that sleep onset itself activates memory consolidation and once the process is triggered it remains effective, even when sleep time is cut short.

Testing Your Vitamin D Levels

Wed, 04 Nov 2009 06:00:00 CST

This question comes from our popular Health After 50 newsletter. A reader asks: Should I have my vitamin D levels tested? Johns Hopkins professor, Dr. Michele Bellantoni answers.

Yes, if you're over 65. Vitamin D deficiency increases your chance of fractures, muscle loss, and bone pain, explains geriatrician Michele Bellantoni, M.D., Medical Director of Hopkins Bayview Care Center and Health After 50 Board Member.

Two blood tests are used to measure vitamin D levels. Most people only need the 25-hydroxy vitamin D test, says Dr. Bellantoni . The other test, referred to as the 1,25-dihydroxy vitamin D test, is used for people with high calcium levels, kidney disease, or certain cancers. Both tests cost around $50 and are covered by Medicare.

If your levels are low, consider taking a vitamin D supplement. Aim to get 800 units of the vitamin daily, says Dr. Bellantoni. Or, if you have no history of skin cancer, you can head outdoors to catch a little sun instead of taking a supplement. "Get out and walk for a few minutes," says Dr. Bellantoni. "It's good for your heart, it's good for your bones, and it's good for your vitamin D." Ten minutes of sunshine a day without any protection (including cosmetics or moisturizers with sunscreen) is probably enough to safely boost vitamin D. Sitting by a window won't work, because the glass blocks the sun's rays, says Dr. Bellantoni.

There are no established guidelines for how often a person should have his or her vitamin D levels checked. Dr. Bellantoni recommends rechecking levels if there has been a considerable reduction in sun exposure or if you have changed your daily intake of supplements over a two-month period.

Drug Safety and the Elderly

Tue, 27 Oct 2009 06:00:00 CDT

A reader asks: In the past year or two, my elderly mother has received a lot of new prescriptions. How can I make sure the drugs will not mix badly and make her sick? In this Health Alert Johns Hopkins answers this question and addresses the larger issue of drug safety and the elderly.

If you are age 65 or older, drug safety takes on special importance. Older adults are more likely to experience side effects from prescription drugs than young people, in part because of physiological changes in the body that commonly accompany aging.

Also, as people age, they tend to develop chronic illnesses such as heart disease, diabetes, high blood pressure, arthritis, and osteoporosis. As a result, it is quite common for the elderly to be on multiple drugs -- a practice referred to as polypharmacy. The average older adult takes between three and five prescription drugs, and many older adults take over-the-counter drugs and supplements as well.

In answer to our reader’s question: Have your mother bag up all her drugs and supplements and bring them to medical appointments for a quick review. Another alternative is to bring a detailed list of drugs and doses. Ask the doctor if all the prescriptions are necessary, whether the doses are at the lowest effective level, and if anything can be done to reduce the number of pills she has to take.

Using combination products that contain fixed doses of drugs often used together is one option to reduce the number of pills taken each day. Or sometimes it is possible to switch to a sustained or extended-release version of a drug that you can take once per day rather than twice or three times. These alternative regimens may not be covered under your mother's insurance, so check before changing prescriptions.

How Old Is Too Old For an Annual PSA Test?

Thu, 15 Oct 2009 06:00:00 CDT

If you are an elderly man, you may wonder if you should continue to have an annual PSA test to screen for prostate cancer. Here are the latest guidelines.

The U. S. Preventive Services Task Force recently recommended that doctors not screen men age 75 and older for prostate cancer. The panel weighed the potential benefits and harms of PSA testing in this population and concluded that the screening was more likely to have a negative impact on these men than a positive one.

The rationale: Prostate cancer is a slow-growing malignancy that may take 10 or more years to produce significant symptoms. Many elderly men will die of another condition before their prostate cancer becomes life threatening. Thus, an abnormal PSA test would lead to the pain and discomfort of a prostate biopsy and unnecessary worry if no cancer is found. If cancer is found and treated, the man will have to contend with side effects, such as sexual dysfunction and incontinence.

Other medical organizations recommend annual screening for men at average risk for prostate cancer beginning at age 50, but they do not address when screening is no longer necessary. And still others recommend screening for all men with a life expectancy of at least 10 years.

Bottom line advice: If you are age 75 or older, discuss the risks and benefits of PSA testing with your doctor. If you get tested and are diagnosed with a low-grade cancer, keep in mind that active surveillance is an option that allows you to be closely monitored but treated only if your disease progresses.

Practical Advice to Help You See Better When You Drive

Fri, 06 Nov 2009 06:00:00 CST

Do you sometimes have trouble seeing clearly when you drive? The American Academy of Opthalmology recommends that everyone between ages 40 and 65 have an eye exam every two to four years. If you're over age 65, you should see your eye doctor every one to two years, particularly to check for conditions such as cataracts, glaucoma, and age-related macular degeneration. Between check ups, if your vision changes or you have trouble driving at night, let your eye doctor know right away. What else can you do? In this Health Alert, Johns Hopkins provides practical advice to help you see better when you drive …

Upgrade Your Eyewear -- You may also want to investigate antireflective lenses for your eyeglasses. These lenses minimize glare and allow more light to enter the eye than regular plastic lenses, which let only 91% of available light enter. Antireflective lenses are especially helpful at night, cutting the reflections on your lenses from streetlamps and headlights.

Polarized sunglasses also may be helpful especially for reducing glare. Polarized lenses have a laminated surface that contains vertical stripes, which allows the light to enter a lens vertically, blocking the horizontal bright light.

Prepare Your Car and Know Your Limits -- There are a number of steps you can take for a safer driving experience.

Keep your headlights, taillights, mirrors, and windshields clean. These may sound like housekeeping details, but they can improve your road vision. Give your eyeglasses a shine before you set out as well.

Keep a spare pair of eyeglasses and sunglasses in your glove compartment so that you never find yourself driving without a pair handy.

If you're buying a car, skip the darkened or tinted windows. Also, pick a model with easy-to-read symbols, large dials, and an instrument panel that brightens well at night. In addition, ask for a rearview mirror that automatically filters out glare.

When you have your car serviced, make sure the lights are at full power and properly aligned so they don't affect the vision of drivers coming toward you.

Plan long road trips with your eyes in mind, stopping every few hours to rest your body and your eyes.

Avoid traveling at night, dawn, and dusk, especially in places you don't know well. And skip the crowded highways for quieter routes.

If you know you're uncomfortable driving, consider taking a refresher class. Refresher classes are offered by the AARP, The Automobile Association of America (AAA), and the National Safety Council. Another option is to work on improving your driving skills with a driving instructor or vision rehabilitation specialist.

If you take prescription medicines, such as antihistamines or blood pressure medication, check with your doctor about whether they may affect your vision.