Diseases & Conditions Archive

How a healthy lifestyle can make a difference in Alzheimer’s prevention.

Alzheimer's disease, the most common form of dementia, is characterized by the accumulation of two types of protein in the brain: tangles (tau) and plaques (amyloid-beta). Eventually, Alzheimer's kills brain cells and takes people's lives.

Alzheimer’s causes

What causes Alzheimer's? We still aren't sure. "For 1% of all cases, there are three genes that determine definitively whether or not you will have Alzheimer's, and all three relate to amyloid-beta production, which in these cases is likely the cause of Alzheimer's," says Dr. Gad Marshall, associate medical director of clinical trials at the Center for Alzheimer Research and Treatment at Harvard-affiliated Brigham and Women's Hospital. "For the other 99%, amyloid and tau are closely associated with Alzheimer's, but many things may contribute to the development of symptoms, such as inflammation in the brain, vascular risk factors, and lifestyle."

Ask the doctor

Q. I hear that there are outbreaks of measles in the United States. I think I had measles when I was young, but I'm not sure. Do I need to worry?

A. The measles virus has been infecting humans for at least 1,000 years. When I was very young, in the 1940s, I got the measles. So did nearly every kid I knew; it is very contagious. I had a high fever, sneezing, coughing, very red eyes, and then a rash on my face and all over my body. Fortunately, I didn't develop the severe complications of measles: pneumonia (which affects one in 20 people with measles) or encephalitis (which affects one in 1,000 and can be fatal). Still, I was miserable for more than a week.

New research aims to capture and eventually cure incessant ringing in the ears.

More than 50 million Americans struggle with tinnitus, a constant or recurring ringing in the ears that ranges from irritating to debilitating. Some treatments work for some people, but none seems to work for everyone.

Tinnitus is a tough condition for doctors to study. "There's no way to measure it directly. The only way we know you have tinnitus is if you tell us. Even if there were a cure, we wouldn't know how it worked because we have to rely on verbal descriptions of what your tinnitus sounds like and how loud it is," says Daniel Polley, director of the Lauer Tinnitus Research Center at Harvard-affiliated Massachusetts Eye and Ear.

Many Americans have fatty liver disease, a condition that can lead to serious liver problems.

If you're not a big drinker, you may not give much thought to the health of your liver. But there might be reason to be concerned. An estimated 64 million Americans have an often-symptomless liver condition called nonalcoholic fatty liver disease (NAFLD), which may put them at risk not only for serious liver disease, but for heart disease as well.

Many people — including doctors — didn't pay much attention to NAFLD until the 1980s, but life insurance companies have had this issue on their radar for years, says Dr. Michelle Lai, an assistant professor of medicine at Harvard Medical School. They knew that an abnormal liver blood test could reflect a lower life expectancy, and they set the premium higher or decline to insure people with the condition, she says.

Q. I've been taking Prilosec for many years for GERD. Recently, I once read that long-term use of proton pump inhibitors could increase the risk of stomach cancer. Your opinion?

A. Prilosec is a pump inhibitor (PPI). These drugs have revolutionized the treatment of gastroesophageal reflux disease (GERD), in which stomach acid flows back into the esophagus and causes heartburn.

The first accurate medical discussion of psoriasis dates back to 1801, but the disease itself is much older. In fact, its very name is borrowed from an ancient Greek word meaning an itchy or scaly condition. About 7 million Americans are plagued by this itching and scaling, and many of them have serious complications involving other organs. Although psoriasis is classified as a dermatologic disease, it doesn't start in the skin, and its damage may be more than skin deep.

Beneath it all

At a basic level, psoriasis is a disorder of the immune system. White blood cells called T-helper lymphocytes become overactive, producing excess amounts of cytokines, such as tumor necrosis factor, interleukin-2, and interferon-gamma. In turn, these chemicals trigger inflammation in the skin and other organs. In the skin, the inflammation produces three characteristic findings: widened blood vessels, accumulation of white blood cells, and abnormally rapid multiplication of keratinocytes, the main cells in the outer layer of the skin. In healthy skin, keratinocytes take about a month to divide, mature, migrate to the skin surface, and slough off to make way for younger cells. But in psoriasis, the entire process is speeded up to as little as three to five days. The result is thickened, red skin that sheds silvery scales of keratinocytes that have matured before their time (see Figure 1).

Water's good. Sugar-free gum helps. But Listerine may give you a dry mouth.

Saliva is like a health drink for your teeth and mouth. The three pints produced by the salivary glands each day contain antibacterial substances that protect teeth from cavities. Saliva contains calcium and phosphorus that teeth absorb. It also functions as an overall lubricant for the mouth, preventing food from sticking to your teeth and gums. By neutralizing gastric acid and keeping the flow of food and drink through the mouth and esophagus on the right course, saliva may help check gastroesophageal reflux (GERD), a leading cause of heartburn.

Q. My platelet count has always been on the low side — 110,000. I don't have any symptoms. But a recent lab report mentioned "giant platelets." Is this something to worry about?

A. Platelets are tiny cell fragments that circulate in the blood and help it clot. They form clots by sticking to one another and by releasing chemicals that promote other aspects of clotting, which is an elaborate, multistep process.

Q. I've tried a lot of things for a fungal infection in one of my toenails, but it just won't go away. What do you know about laser treatment for toenail fungus?

A. Two lasers using different types of laser energy have attracted attention as treatments for fungal infection of the toenails, a condition called onychomycosis (pronounced oh-nee-koh-my-KOH-sis), which can also affect the fingernails. The theory is that a precisely directed laser can eliminate the fungus without harming the surrounding nail tissue. The underlying technologies are already in use for other conditions, including cataract surgery, dental work, and hair removal. Although there is some laboratory evidence that lasers can squelch fungal organisms, clinical studies in humans thus far are limited.

Heart and lung issues are often to blame for breathlessness. But an accurate diagnosis may require advanced testing.

Like your heartbeat, the regular inhale and exhale of your breathing is something you usually don't notice — until something doesn't feel quite right. Shortness of breath can result from a range of problems, including an allergic reaction, an anxiety attack, or anemia. But most often, the underlying cause is a heart or lung condition.

"Because these two organ systems are so intertwined, one always affects the other," says Dr. Aaron B. Waxman, who directs the Pulmonary Vascular Disease Program at Harvard-affiliated Brigham and Women's Hospital. In fact, about 60% of people with heart disease also have a lung disease. As a result, it's not always easy to distinguish cardiac and pulmonary issues, he says.