Diseases & Conditions

The human body is a remarkable structure. It's designed to efficiently manage the wear and tear of everyday life and fend off all sorts of threats. Most of us are healthy for most of our lives. But we're also susceptible to hundreds of injuries, diseases, and conditions. Some are quite common, others are extremely rare. Here are some of the most common conditions that affect humans.


Diseases & Conditions Articles

Benefits of moderate sun exposure

Dr. Robert S. Stern, chair of the Department of Dermatology at Harvard-affiliated Beth Israel Deaconess Medical Center , calls them "solar-phobes": people so concerned about getting skin cancer that they stay inside or cover every bit of skin. "They cover up like they were going out into the Arabian Desert ," he says. The marketing of ultrablocking sunscreens and special sun-protective clothing plays into these fears. There's no getting around the fact that sunlight is hard on your skin. Age gets blamed for wrinkles and rough, dry skin. But the real culprit is a combination of age and sun that dermatologists call photoaging. The short UVB wavelengths that cause sunburn can also damage DNA and suppress the skin's immune system. The longer, more penetrating UVA wavelengths may create highly reactive oxygen molecules capable of damaging skin cell membranes and the DNA inside. The relationship between sun exposure and skin cancer risk isn't as straightforward as you might think. Genes are a factor, of course: Some protect, some promote. So is skin type: People with pale skin who sunburn easily and don't tan are more likely to get sun-related skin cancer. As for exposure, the "dose" and its timing are crucial. Several studies have suggested that suddenly getting a lot of sun is more dangerous then steady exposure over time. More »

Diagnosing and treating irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic disorder characterized by recurrent bouts of constipation, diarrhea, or both, as well as abdominal pain, bloating, and gas. IBS is a functional disorder, which means that it's not attributable, as far as we know, to any underlying disease process or structural abnormality. It's thought to involve various, often interacting, factors — infection, faulty brain-gut communication, heightened pain sensitivity, hormones, allergies, and emotional stress. The good news is that IBS doesn't increase the risk for more serious conditions, such as ulcerative colitis or colon cancer. On the other hand, a disorder resulting in (at best) annoying and (at worst) debilitating and worrisome symptoms with no known cause can be difficult to diagnose and treat, not to mention live with. Managing IBS typically involves some trial and error, which can be challenging for patients and clinicians alike. Various tests or procedures may be ordered to rule out other conditions. Many diverse therapies, not all of them proven, are used in treating the symptoms, including antibiotics, antispasmodics, antidepressants, dietary changes, relaxation techniques, and psychotherapy, as well as drugs to relieve constipation and diarrhea. In the past doctors often ordered extensive testing (complete blood count, thyroid function test, stool testing for parasites, and abdominal imaging) before diagnosing IBS. This is usually unnecessary for people with typical IBS symptoms who have no family history of colon cancer, inflammatory bowel disease, or celiac sprue — and no "alarm symptoms," including rectal bleeding, weight loss, or iron-deficiency anemia. More »

New information on fibromyalgia

People who suffer from fibromyalgia know something is not right, even though they appear fine otherwise. This painful condition is not well understood, making it that much more difficult to diagnosis and treat. New research offers a better understanding of the disorder and may provide doctors with a way to diagnose the condition and monitor treatment.Fibromyalgia causes mild to severe pain in the joints, tendons, and muscles of the body. Other symptoms may include fatigue and disrupted sleep. Fibromyalgia can last indefinitely, but does not seem to progress or affect survival. Although the condition is traditionally classified as a rheumatic disease, researchers believe fibromyalgia has its roots in the nervous system. This idea is supported by the results of a study published in the May 2003 issue of Arthritis and Rheumatism. The study involved sensory testing of 85 individuals suffering from fibromyalgia and 40 healthy volunteers. Using testing of the pain reflex, various temperatures, mechanical pressure, and electrical stimuli, the researchers discovered that patients with fibromyalgia have highly excitable pain centers in their nervous systems compared to healthy individuals. This translates to higher pain sensitivity and lower tolerance for pain than the average person. A simple pinprick may be excruciatingly painful for someone with fibromyalgia. The results also suggest measurement of the pain reflex may be one way to determine which patients would benefit from painkillers that target the central nervous system, such as antidepressants. A low dose of the antidepressant amitriptyline (Elavil) is already known to be effective at diminishing the pain associated with fibromyalgia.Besides the possible use of antidepressants to combat the pain, a number of other strategies are effective at alleviating the pain. These include pain relief medications including acetaminophen, aspirin, and nonsteroidal anti-inflammatory drugs. Doctors recommend low-impact exercise, such as walking, swimming, and cycling, as well as stretching to ease stiffness. Good sleep habits are also important to ensure the body has time to rest. More »

Pancreatic cancer: Symptoms, treatment, and prevention

Hard to detect and quick to spread, pancreatic cancer is among the deadliest of cancers. Scientists hope that genetic research will make it more like other cancers-a treatable disease. But even if it's caught while confined to the pancreas-and it rarely is-just 16% of patients are alive five years after the initial diagnosis. By comparison, the five-year survival rate for localized breast cancer is 86%. If the cancer has spread beyond the pancreas, the likelihood of living another five years is just 2%. Only the statistics for liver cancer are as grim. Fortunately, pancreatic cancer is uncommon compared with other major cancers. About 50,000 new cases are diagnosed every year in the United States, in contrast to about 250,000 new cases of breast cancer, and 225,000 new cases of lung cancer. But because it's so untreatable, pancreatic cancer causes about 40,000 deaths each year. It is the 4th leading cause of cancer death. No one knows exactly what causes pancreatic cancer. Like many cancers, it's an older person's disease - the median age at diagnosis is 71. Because Americans are living longer, there are more cases now than a half-century ago. Pancreatic cancer does run in families. Former President Jimmy Carter's father, brother, and two sisters died of the disease. Familial cases account for 5%-15% of the total. More »

When You Visit Your Doctor

We know how helpful it is to have "when you visit your doctor" questions handy at your medical appointments. Here at Harvard Health Publishing, we have prepared these additional sets of questions you can print out and take with you so you'll know what to discuss with your doctor. Here are some of the topics available to help you partner with your doctor to get the best medical care: Parkinson'’s disease, cataracts, gallstones, pregnancy, and many more. Acne After Hodgkin's Disease Treatment More »

Essential tremor—TheFamily Health Guide

We use our hands constantly. Every morning millions of people shower, shave, get dressed, eat breakfast — tasks that would be incredibly difficult without steady hands. For an estimated 10 million Americans with a neurological disorder called essential tremor, shaking of their arms and other body parts makes it difficult or even impossible to perform the simplest of movements. The condition, which affects the muscles of the hands, head, and voice, is often mistaken for Parkinson's patients. But essential tremor is 5-10 times more common than Parkinson's disease. Most people diagnosed with essential tremor have action tremor, which means they shake when they move, and some develop a distinctive nodding or shaking of the head. People with Parkinson's usually experience tremors at rest, along with stiffness and slowness of movement. But there's some overlap between the two conditions. Some studies show that 90% of Parkinson's patients have action tremor and 20% of people with essential tremor have tremor at rest. Both conditions cause a loss of the sense of smell, but in essential tremor it's usually milder. Patients with essential tremor can go on to develop Parkinson's disease, but how many do so isn't known. More »

Heart attacks in women

Although hard-to-read heart attacks happen to both men and women, they are more common in women. One reason for this is that men's symptoms initially set the standard for recognizing heart trouble. Now a growing body of research shows that women can experience heart attacks differently than men. Understanding sex differences in heart disease is important. Heart disease is the leading cause of death for women. Although it mostly affects older women, it isn't rare in younger women. One in 10 of all women who die from heart disease or a stroke are under age 65, and this age group accounts for one-third of heart- or stroke-related hospitalizations. Even so, younger women and their doctors don't necessarily suspect a heart attack even when all the signs are there. In a survey of more than 500 women who survived heart attacks, 95% of them said they noticed that something wasn't right in the month or so before their heart attacks. Two most common early warning signs were fatigue and disturbed sleep. Some women, for example, said they were so tired they couldn't make a bed without resting. More »

Welcome Newsweek Readers

The faculty of Harvard Medical School worked with the editorial staff of Newsweek to write articles of interest about health and medicine. Harvard Medical School publishes books, newsletters, and special health reports through its Harvard Health Publishing division. Issue date: April 27, 2009 Issue date: February 23, 2009 More »

The lowdown on eye exercises

If you wear glasses or contacts, chances are you've been at least a little bit tempted to investigate the infomercials and books promoting eye exercises to improve your eyesight without surgery. Some programs even claim that faithful adherents may be able to give up their glasses. If this sounds too good to be true, that's because it is. Purveyors of self-directed eye exercise programs have not conducted randomized trials to verify the effectiveness of their programs, and there is no medical evidence for their oft-stated claim that wearing lenses weakens the eyes and necessitates ever-stronger prescription eyewear. Furthermore, some programs are based on ideas that don't quite square with the anatomy and physiology of vision. Practiced faithfully, eye exercises may actually help delay the need for glasses or contacts in some people. But you don't need to buy a special program of exercises or follow prescribed visual gymnastics to accomplish these things. If your eyes are tired from excessive close-up work — such as staring at the computer — visual breaks to focus on objects at longer distances are a good idea. And it's important to encourage your visual system to do its best. More »

What causes dry mouth — and what treats it—The Family HealthGuide

The three pints of saliva that the average healthy adult produces every day may be the most underrated body fluid. Saliva jump-starts digestion, dissolving and adding moisture to food so it's easier to swallow. It breaks down starch with a digestive enzyme called amylase. Saliva contains bicarbonate, which acts as a buffering agent that offsets the enamel-corroding acid produced by bacteria. Salivary antibodies and protein also fend off dental bacteria as well as other infectious agents. Saliva helps you speak clearly by keeping your mouth moist and allowing the tongue — which is essential to forming many sounds — to stay agile. Compared with other medical problems, dry mouth, or xerostomia, may be little more than an annoyance: eating is a little less pleasant and speech a little more difficult. But for people who have little or no saliva, persistent xerostomia is a serious and often uncomfortable condition that can jeopardize oral health. It makes eating and swallowing difficult, causes bad breath, and may irritate mouth tissues, leaving them more vulnerable to infection. Dry mouth also increases the risk for tooth decay and gum disease. The treatment of dry mouth depends on its cause. For a long time, many doctors thought xerostomia was a natural consequence of aging. Now most experts agree that the vast majority of xerostomia cases are side effects of the many medications older people take, rather than aging itself. The culprits include blood pressure medications, antidepressants, muscle relaxants, antihistamines, asthma drugs, and painkillers. Xerostomia can also be caused by radiation treatment for head and neck cancer; in killing the cancer, the radiation also knocks out the salivary glands. Other sources of the condition are chemotherapy drugs and various chronic diseases, including diabetes, Parkinson's disease, and an autoimmune condition called Sjogren's syndrome. More »