ULCER, APHTHOUS

Small and out-of-sight, but painful, persistent and annoying. That's what canker sores, also called aphthous ulcers (aphthae), are like for people who experience them. These shallow ulcers in your mouth can make eating and talking uncomfortable. They may occur on your tongue, on your soft palate, inside your cheeks or lips, and at the base of your gums.

Canker sores differ from cold sores in that they occur in the soft tissues of your mouth and aren't contagious. Conversely, cold sores rarely develop in the soft tissues of your mouth and are extremely contagious because they're caused by the herpes virus.

Canker sores are common, but the cause in many cases is unknown. Canker sores can occur at any age, but often first appear when you are between 10 and 40 years of age.

Often, treatment isn't necessary. Pain often decreases after several days, and canker sores usually heal within one to three weeks. Occasionally, severe canker sores can develop that are larger than 1 centimeter in diameter or last longer than two weeks or both.

ULCER, DUODENAL

Too much stress, too much spicy food, and you may be headed for an ulcer — or so the thinking used to go.

Peptic ulcers are open sores that develop on the inside lining of your stomach, upper small intestine or esophagus. The most common symptom of a peptic ulcer is pain.

Not long ago, the common belief was that peptic ulcers were a result of lifestyle. Doctors now know that a bacterial infection or medications — not stress or diet — cause most ulcers of the stomach and upper part of the small intestine (duodenum). Esophageal ulcers may also occur and are typically associated with the reflux of stomach acid.

Depending on their location, ulcers have different names:

• Gastric ulcer. This is a peptic ulcer that occurs in your stomach.
• Duodenal ulcer. This type of peptic ulcer develops in the first part of the small intestine (duodenum).
• Esophageal ulcer. An esophageal ulcer is usually located in the lower section of your esophagus. It's often associated with chronic gastroesophageal reflux disease (GERD).

Peptic ulcers are common. The good news is that oftentimes successful treatment of ulcers takes just a few weeks.

ULCERATIVE COLITIS

An estimated more than 1 million Americans have ulcerative colitis or Crohn's disease, the two most common forms of inflammatory bowel disease (IBD). These conditions, which can be painful and debilitating, cause chronic inflammation of the digestive tract.

Ulcerative colitis and Crohn's disease are very similar — so similar, in fact, that they're often mistaken for one another. Both inflame the lining of your digestive tract, and both can cause severe bouts of watery diarrhea and abdominal pain. But Crohn's disease can occur anywhere in your digestive tract, often spreading deep into the layers of affected tissues. Ulcerative colitis, on the other hand, usually affects only the innermost lining (mucosa) of your large intestine (colon) and rectum.

Ten to 15 people out of every 100,000 in the United States develop ulcerative colitis, while about seven in 100,000 get Crohn's disease. No one knows exactly what causes these diseases, although your immune response and certain genetic and environmental factors may play a role.

There's no known medical cure for either ulcerative colitis or Crohn's disease. However, therapies are available that may dramatically reduce your signs and symptoms and even bring about a long-term remission

ULTRASOUND

A diagnostic imaging procedure that uses high-frequency sound waves to create a picture of internal body structures on a video screen.

UNDERACTIVE THYROID

Your thyroid is a butterfly-shaped gland located at the base of your neck, just below your Adam's apple. Although it weighs less than an ounce, the thyroid gland has an enormous effect on your health. All aspects of your metabolism, from the rate at which your heart beats to how quickly you burn calories, are regulated by thyroid hormones.

As long as your thyroid releases the proper amounts of these hormones, your system functions normally. But sometimes your thyroid doesn't produce enough hormones, upsetting the balance of chemical reactions in your body. This condition is known as hypothyroidism, or underactive thyroid disease.

Women, especially those older than 40, are more likely to have an underactive thyroid than men are. By age 60, as many as 17 percent of American women may have hypothyroidism. The condition seldom causes symptoms in the early stages, but over time, untreated hypothyroidism can cause a number of heath problems.

The good news is that thyroid function tests have improved considerably in recent years, and early diagnosis is easier. In addition, treatment with synthetic thyroid hormone is usually simple and effective once the proper dosage is established. Natural treatment options also exist.

URINARY INCONTINENCE

Do you have trouble controlling when you urinate? Do you leak urine when you cough or sneeze? Do you suddenly need to go to the bathroom so badly that you're not sure you're going to make it in time — and sometimes you don't? Does a fear of wetting yourself and smelling of urine keep you from activities?

The loss of bladder control — urinary incontinence — is an all too common, often embarrassing and frustrating problem for as many as 13 million Americans. If you answered yes to any of the above questions, you may count among them.

Although common, urinary incontinence isn't necessarily a normal part of aging or, in women, an inevitable consequence of childbirth or changes after menopause. It's a medical condition that can have many different causes, some relatively simple and temporary and others more involved and long term.

If you're having trouble with incontinence, don't hesitate to see your doctor. In many cases, incontinence can be eliminated. Even if it can't be completely eliminated, modern products and ways of managing urinary incontinence can ease your discomfort and inconvenience.

URINARY TRACT INFECTION

A urinary tract infection (UTI) is an infection that begins in your urinary system. UTIs can be painful and annoying. They can also become a serious health problem if the infection spreads to your kidneys.

Women are most at risk of developing a UTI. In fact, one in five women will likely develop a UTI during her lifetime, and many will experience more than one.

The urinary system is composed of the kidneys, ureters, bladder and urethra. All play a role in removing waste from your body. The kidneys, a pair of bean-shaped organs in your upper-posterior abdomen, filter waste from your blood. Tubes called ureters carry urine from your kidneys to your bladder, where it is stored until it exits the body through the urethra. All of these components can become infected, but most infections involve the lower tract — the urethra and the bladder.

Antibiotics are the typical treatment for urinary tract infections. And, you can take steps to reduce your chance a getting a UTI in the first place.

URTICARIA

Hives — also known as urticaria — are raised, red, often itchy welts (wheals) of various sizes that appear and disappear on the skin. Angioedema, a similar swelling, causes large welts deeper in the skin, especially near the eyes and lips. A more serious condition — hereditary angioedema (HAE) — is an uncommon, inherited disorder, which can cause sudden, severe and rapid swelling of the face, arms, legs, hands, feet, genitalia, digestive tract and airway.

As many as one in five people experiences acute hives or angioedema at one time or another. HAE affects only about 6,000 people in the United States.

In most cases, hives and angioedema are harmless and leave no lasting marks. The common treatment is medications. Serious angioedema can be life-threatening if swelling causes your throat or tongue to block your airway and leads to loss of consciousness.

UTERINE CANCER

Endometrial cancer is one of the most common cancers in American women. In fact, about 40,000 American women receive a diagnosis of endometrial cancer each year, making it the fourth most common cancer found in women — after breast cancer, lung cancer and colon cancer.

Endometrial cancer usually begins in the lining of the uterus (endometrium). The uterus is a hollow, pear-shaped pelvic organ. Endometrial cancer most often occurs after the reproductive years, between the ages of 60 and 70. Endometrial cancer is sometimes called uterine cancer, but there are other cells in the uterus that can become cancerous — such as muscle or myometrial cells. These form much less common cancers called sarcomas and account for less than 5 percent of uterine cancers.

Endometrial cancer is often detected at an early stage because it frequently produces vaginal bleeding between menstrual periods or after menopause. If discovered early, this slow-growing cancer is likely to be confined to the uterus. Removing the uterus surgically often eliminates the cancer. In fact, stage I endometrial cancer is successfully treated more than 90 percent of the time. Unfortunately, not everyone can be successfully treated because the cancer may have spread beyond the uterus at the time of diagnosis. About 7,000 American women die each year of endometrial cancer.

UTERINE FIBROIDS

Uterine fibroids are among the most common tumors in women. These noncancerous growths of the uterus appear during your childbearing years. Also called fibromyomas, leiomyomas or myomas, uterine fibroids aren't associated with an increased risk of uterine cancer and almost never develop into cancer. Most of the time, uterine fibroids aren't harmful.

As many as three out of four women have uterine fibroids, but most are unaware of them as they often cause no signs or symptoms. Your doctor may discover them incidentally during a pelvic exam or prenatal ultrasound. Fibroids cause problems for about one in four women, most frequently during their 30s or 40s.

Fibroids can require emergency treatment if they cause sudden, sharp pelvic pain. But this is rare. In general, fibroids cause no problems and seldom require treatment. Medical therapy and surgical procedures can shrink or remove fibroids if they cause discomfort or troublesome symptoms.