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
The bacteria that cause disease are remarkably resilient and can develop ways to evade the drugs meant to kill or weaken them. This phenomenon is called antibiotic resistance and it is due largely to the growing, and often careless, use of antibiotics.
Today, bacterial infections in the United States and throughout the world are becoming resistant to the drugs we rely on to treat them. Antibiotic resistance has been called one of the world's most pressing public health problems. The smart use of antibiotics is the key to controlling the spread of antibiotic resistant bacteria and the rise of superbugs—bacteria that cause infections that are difficult if not impossible to treat.
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.
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.
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
Interstitial cystitis is a chronic inflammation of the bladder that causes people to urinate -- sometimes painfully -- as often as 40, 50, or 60 times a day. Their quality of life, research suggests, resembles that of a person on kidney dialysis or suffering from chronic cancer pain. Not surprisingly, the condition is officially recognized as a disability.
There's no cure for interstitial cystitis, but many treatments offer some relief, either on their own or in combination.
Treatment (see chart) is aimed at relieving pain and reducing inflammation. The two main approaches are oral medications and bladder instillations -- drugs that are introduced into the bladder by catheter and held for 15 minutes. The procedure usually takes place in a physician's office, but in some cases these drugs can be self-administered at home.
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.
"Stay away from me! I don't want to get sick, too." Most of us have had to utter those words to a family member, friend, or colleague who was sneezing or coughing incessantly. But how do we know how great the chances of catching someone's cold or other illness really are? A medical review published in the New England Journal of Medicine tells us when to exercise concern over eight respiratory tract infections.
(Respiratory Syncytial Virus, RSV)
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.