All Diseases

Genital herpes is a common sexually transmitted infection that affects men and women. Features of genital herpes include pain, itching and sores in your genital area. But you may have no signs or symptoms of genital herpes. If infected, you can be contagious even if you have no visible sores.

The herpes simplex virus (HSV) causes genital herpes. Sexual contact is the primary way that the virus spreads. After the initial infection, the virus lies dormant in your body and can reactivate several times a year.

There's no cure for genital herpes, but medications can ease symptoms and reduce the risk of infecting others. Condoms also can help prevent transmission of the virus.

Genital warts are one of the most common types of sexually transmitted infections. At least half of all sexually active people will become infected with human papillomavirus (HPV), the virus that causes genital warts, at some point during their lives. Women are somewhat more likely than men to develop genital warts.

As the name suggests, genital warts affect the moist tissues of the genital area. Genital warts may look like small, flesh-colored bumps or have a cauliflower-like appearance. In many cases, the warts are too small to be visible.

Like warts that appear elsewhere on your body, genital warts are caused by the human papillomavirus (HPV). Some strains of genital HPV can cause genital warts, while others can cause cancer. Vaccines can help protect against certain strains of genital HPV.

Geographic tongue is a harmless condition affecting the surface of your tongue. The tongue is normally covered with tiny, pinkish-white bumps (papillae), which are actually short, fine, hair-like projections. With geographic tongue, patches on the surface of the tongue are missing papillae and appear as smooth, red "islands," often with slightly raised borders.

These patches (lesions) give the tongue a map-like, or geographic, appearance. The lesions often heal in one area and then move (migrate) to a different part of your tongue. Geographic tongue is also known as benign migratory glossitis.

Although geographic tongue may look alarming, it doesn't cause health problems and isn't associated with infection or cancer. Geographic tongue can sometimes cause tongue discomfort and increased sensitivity to certain substances.

Gastroesophageal reflux disease (GERD) is a chronic digestive disease. GERD occurs when stomach acid or, occasionally, stomach content, flows back into your food pipe (esophagus). The backwash (reflux) irritates the lining of your esophagus and causes GERD.

Both acid reflux and heartburn are common digestive conditions that many people experience from time to time. When these signs and symptoms occur at least twice each week or interfere with your daily life, or when your doctor can see damage to your esophagus, you may be diagnosed with GERD.

Most people can manage the discomfort of GERD with lifestyle changes and over-the-counter medications. But some people with GERD may need stronger medications, or even surgery, to reduce symptoms.

Gestational diabetes develops during pregnancy (gestation). Like other types of diabetes, gestational diabetes affects how your cells use sugar (glucose). Gestational diabetes causes high blood sugar that can affect your pregnancy and your baby's health.

Any pregnancy complication is concerning, but there's good news. Expectant moms can help control gestational diabetes by eating healthy foods, exercising and, if necessary, taking medication. Controlling blood sugar can prevent a difficult birth and keep you and your baby healthy.

In gestational diabetes, blood sugar usually returns to normal soon after delivery. But if you've had gestational diabetes, you're at risk for type 2 diabetes. You'll continue working with your health care team to monitor and manage your blood sugar.

Giant cell arteritis is an inflammation of the lining of your arteries — the blood vessels that carry oxygen-rich blood from your heart to the rest of your body. Most often, it affects the arteries in your head, especially those in your temples. For this reason, giant cell arteritis is sometimes called temporal arteritis or cranial arteritis.

Giant cell arteritis frequently causes headaches, jaw pain, and blurred or double vision. Blindness and, less often, stroke are the most serious complications of giant cell arteritis.

Prompt treatment of giant cell arteritis is critical in order to prevent permanent tissue damage and loss of vision. Corticosteroid medications usually relieve symptoms of giant cell arteritis and may prevent loss of vision. You'll likely begin to feel better within days of starting your treatment.

Giardia infection (giardiasis) is an intestinal infection caused by a microscopic parasite that's found worldwide, especially in areas with poor sanitation and unsafe water. Giardia infection is marked by abdominal cramps, bloating, nausea and bouts of watery diarrhea.

Giardia infection is a waterborne infection and can be caused by parasites found in backcountry streams and lakes, as well as in municipal water supplies, swimming pools, whirlpool spas and wells. Giardia infection can also be transmitted through food and person-to-person contact.

Giardia infections usually clear up within a few weeks. But you may have intestinal problems long after the parasites are gone. Several drugs are generally effective against giardia parasites, but not everyone responds to them. Prevention is your best defense.

Gilbert's syndrome is a common, mild liver condition in which the liver doesn't properly process a substance called bilirubin. Bilirubin is produced by the breakdown of red blood cells.

Gilbert's (zheel-BAYRZ) syndrome typically is harmless and doesn't require treatment.

Gilbert's syndrome is caused by an inherited gene mutation. You're born with Gilbert's syndrome, though it often goes undiscovered for many years. Gilbert's syndrome is often discovered by accident, such as when you have a blood test that shows elevated bilirubin levels.

Gilbert's syndrome is also known as constitutional hepatic dysfunction and familial nonhemolytic jaundice.

Gingivitis is a common and mild form of gum disease (periodontal disease) that causes irritation, redness and swelling (inflammation) of your gums. Because gingivitis can be mild, you may not be aware that you have the condition. But it's important to take gingivitis seriously and treat it promptly. Gingivitis can lead to much more serious gum disease (periodontitis) and eventual tooth loss.

The most common cause of gingivitis is poor oral hygiene. Good oral health habits, such as brushing at least twice a day, flossing daily and getting regular dental checkups, can help prevent gingivitis.

Glaucoma is not just one eye disease, but a group of eye conditions resulting in optic nerve damage, which may cause loss of vision. Abnormally high pressure inside your eye (intraocular pressure) usually, but not always, causes this damage.

Glaucoma is one of the leading causes of blindness in the United States. Glaucoma can damage your vision so gradually you may not notice any loss of vision until the disease is at an advanced stage. The most common type of glaucoma, primary open-angle glaucoma, has no noticeable signs or symptoms except gradual vision loss.

Early diagnosis and treatment can minimize or prevent optic nerve damage and limit glaucoma-related vision loss. It's important to get your eyes examined regularly, and make sure your eye doctor measures your intraocular pressure.