In-depth

Abdominal aortic aneurysm

An abdominal aortic aneurysm is a dangerous condition in which a part of your body's main artery (aorta) is enlarged and in danger of rupturing.

Addison's disease

Addison's disease occurs when your adrenal glands produce insufficient amounts of certain important hormones. Treatment may include taking corticosteroids.

Alcoholic hepatitis

Alcohol can severely damage your liver — even moderate drinkers aren't immune. Learn more about this serious liver disease.

Anaphylaxis

Anaphylaxis is the most serious type of allergic reaction. It often occurs rapidly after exposure to an allergen and may be life-threatening.

Antibiotic-associated diarrhea

Antibiotics save lives, but they can also have side effects. The most common are mild to severe diarrhea and a serious type of colitis.

Appendicitis

Ascariasis

Ascariasis is a common type of roundworm infection found worldwide. It's spread by poor hygiene and improper sanitation. Infections are effectively treated with medication.

Behcet's disease

Behcet's disease affects several body systems and causes a variety of signs and symptoms. Find out what it is and how it's treated.

Bile reflux

Bile reflux — the backwash of bile from the small intestine into the stomach and esophagus — can cause ongoing inflammation and lead to serious complications.

Bladder stones

Bladder stones are small masses of minerals in your bladder — often forming as a result of an enlarged prostate, nerve damage or infection.

Blastocystis hominis infection

A microscopic parasite causes Blastocystis hominis infection. Experts disagree as to whether this infection causes diarrhea and other associated signs and symptoms.

Blind loop syndrome

Blind loop syndrome occurs when a portion of bowel is bypassed. The condition is most often a complication of abdominal surgery.

Botulism

Botulism, a rare and dangerous condition, is usually the result of eating food — often canned goods contaminated by bacteria that release a powerful toxin.

C. difficile

C. difficile can be a life-threatening infection. It typically develops when antibiotics destroy other bacteria in your intestines, allowing C. difficile to flourish.

Carcinoid tumors

Carcinoid tumors are rare, slow-growing cancerous tumors that most often occur in the gastrointestinal tract or in the lungs.

Cardiogenic shock

Cardiogenic shock is a life-threatening complication usually of a heart attack. Cardiogenic shock treatments can be effective, but must be provided immediately.

Celiac disease

Celiac disease is an immune reaction to gluten, a protein found in certain foods. As a result, the body is unable to absorb some important nutrients.

Chlamydia

Are you worried you might have chlamydia? Find out how this common sexually transmitted infection is diagnosed and treated.

Chronic lymphocytic leukemia

Chronic lymphocytic leukemia is a cancer of the blood and bone marrow. Unlike other cancers, this form of leukemia doesn't always initially require treatment.

Churg-Strauss syndrome

Churg-Strauss syndrome is a rare disorder marked by blood vessel inflammation that affects organs throughout the body. Asthma is the most common sign.

Colon cancer

Colon cancer and rectal cancer combined are the second-leading cause of cancer-related deaths in the United States. Regular screening tests can help reduce your risk.

Constipation in children

Constipation in children is common. Often, simple changes in diet and routine are helpful.

Cyclic vomiting syndrome

Cyclic vomiting syndrome can last for hours or days and shares many triggers with migraines.

Diabetic ketoacidosis

Diabetic ketoacidosis is a serious diabetes complication. Learn the warning signs — and know when to seek emergency care.

Diabetic neuropathy

Diabetes can damage nerves throughout your body — a condition known as diabetic neuropathy. Nerve damage can cause pain, disability and other serious complications.

Diarrhea

Diarrhea can have many triggers, including viruses, bacteria, parasites and certain medications. Though unpleasant, most cases of diarrhea go away without treatment.

Ectopic pregnancy

An ectopic pregnancy can't continue normally — but prompt treatment can help prevent life-threatening blood loss.

Egg allergy

Egg allergy can cause a serious reaction in children and adults. Here's how to recognize egg allergy symptoms, and what to do if a severe reaction occurs.

Encopresis

Encopresis occurs when a child resists having bowel movements, causing stool to collect in the colon and rectum. Leakage of liquid stool also is common.

Enlarged liver

You can get an enlarged liver from a number of medical problems or personal habits. Treatment depends on what's causing the enlargement.

Enlarged spleen

An enlarged spleen is usually a sign of an underlying problem. Treatment varies, depending on what's causing the enlargement.

Epididymitis

Epididymitis is an inflammation of the tube at the back of the testicle (epididymis). The condition is usually treated with antibiotics.

Fibromuscular dysplasia

Fibromuscular dysplasia is a rare, but treatable, condition in which the arteries to your kidneys, brain or abdomen narrow, reducing blood flow to your organs.

Food allergy

Food allergy symptoms can make you miserable. Unfortunately, there's no cure — but there are steps you can take to keep your symptoms in check.

Food poisoning

Food poisoning has many forms, and some can be serious. Here's how to recognize food poisoning and ways to prevent getting sick.

Gallstones

Gallstones often don't cause symptoms. But if you have a gallbladder attack, you're not likely to forget it.

Gas and gas pains

Intestinal gas can be embarrassing and sometimes painful. But a few simple measures can often provide relief.

Giardiasis

Giardia infection is a common waterborne illness. Learn the symptoms and reduce your risk.

Gonorrhea

Gonorrhea is a highly contagious sexually transmitted infection. Without treatment, serious complications can occur.

Hantavirus pulmonary syndrome

Hantavirus pulmonary syndrome is initiated by a rodent-carried virus that infects the lung tissues, bringing on flu-like symptoms, respiratory problems and even death.

Headaches in children

Children of all ages experience headaches, but the causes aren't all the same. Here's how to help your child.

Heart attack

Hemolytic uremic syndrome (HUS)

Hemolytic uremic syndrome is an uncommon condition that can cause life-threatening kidney failure, especially for children and older adults.

Henoch-Schonlein purpura

Henoch-Schonlein purpura causes inflammation of small blood vessels (vasculitis) and often a purplish rash. It's most common in children ages 2 to 6.

Hepatitis A

Hives and angioedema

Hives and angioedema — Comprehensive overview covers symptoms, causes, treatment of these common allergic disorders.

Hyperglycemia in diabetes

Hyperglycemia in diabetes — Comprehensive overview covers causes, symptoms and treatments of high blood sugar.

Indigestion

Indigestion can ruin meals and make you feel uncomfortable. Take steps to prevent symptoms like upset stomach, bloating and pain.

Inflammatory bowel disease (IBD)

Inflammatory bowel disease can be painful and debilitating, and it can cause life-threatening complications. Find out more about treating this digestive system disorder.

Intestinal ischemia

Intestinal ischemia occurs when the blood supply to your digestive system is reduced. Abdominal pain is a common symptom. Several treatment options are available.

Intestinal obstruction

Intestinal obstruction — a serious condition that requires prompt medical attention — occurs when a blockage of the intestine prevents food or fluid from passing through.

Ischemic colitis

Ischemic colitis is a disorder in which the colon becomes inflamed, usually due to a disruption of blood flow.

Kawasaki disease

Kawasaki disease — the leading cause of acquired coronary disease in children — causes artery wall inflammation throughout the body. It affects children younger than age 5.

Kidney infection

Lactose intolerance

Lactose intolerance means you can't fully digest milk sugar (lactose). Though it's generally not dangerous, the symptoms can be uncomfortable.

Liver cancer

The risk of liver cancer may be reduced by protecting yourself from serious liver diseases such as cirrhosis and hepatitis B and C.

Liver hemangioma

Liver hemangioma is the most common type of noncancerous (benign) liver mass. Learn how doctors treat liver hemangioma.

Mesenteric lymphadenitis

Mesenteric lymphadenitis is an inflammation of the lymph nodes in the tissue that attaches various organs to your abdominal wall (mesentery). It mainly affects children.

Mesothelioma

Mesothelioma is a type of cancer closely linked to asbestos exposure. Find out the signs and symptoms of malignant mesothelioma and how to protect yourself.

Miscarriage

Miscarriage can be heartbreaking. It might help to understand possible causes and treatment options, as well as what to expect for the future.

Neuroblastoma

Neuroblastoma most commonly affects children age 5 and younger. It's the most common form of cancer in babies.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is associated with obesity and diabetes. Lifestyle changes may prevent it from becoming serious.

Non-Hodgkin's lymphoma

Non-Hodgkin's lymphoma is cancer originating in the lymphatic system. It's caused by abnormal white blood cells, and often the only sign is swollen lymph nodes.

Norovirus infection

Noroviruses cause an intestinal flu-like illness that typically resolves within days. Norovirus infection is highly contagious, especially in closed settings like hospitals and cruise ships.

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) — Comprehensive overview covers symptoms, treatment of this complication of infertility treatment.

Pancreatic cancer

Pancreatic cancer is often fatal. Find out which new treatments offer hope.

Pancreatic cysts

Most cysts in the pancreas aren't malignant, but tests are needed to determine the best course of treatment.

Pancreatitis

The pain of pancreatitis, an inflammation of the pancreas, can last for days, or in chronic cases, for years. Pancreatitis can lead to serious complications.

Peritonitis

Peritonitis is an infection of the membrane that lines your inner abdominal wall and covers the organs within your abdomen (peritoneum).

Pinworm infection

Pinworms are intestinal parasites common in children and easily spread within families. Effective treatments include medications and good hygiene.

Placental abruption

Placental abruption is a dangerous pregnancy complication. Control your risk factors — and know when to seek emergency care.

Plague

Plague is a disease carried by rats and other rodents. The risk of developing plague is low, and most cases occur in Africa.

Porphyria

Porphyria is a group of inherited disorders that result from buildup of natural chemicals call porphyrins, which can cause nervous system and skin problems.

Postpartum preeclampsia

Postpartum preeclampsia — Comprehensive overview covers symptoms and treatment of this post-pregnancy condition.

Primary biliary cirrhosis

Primary biliary cirrhosis begins with inflammation in the liver's small bile ducts, but eventually can lead to damage and scarring in the liver itself.

Proctitis

Proctitis is an inflammation of the lining of the rectum.

Pseudomembranous colitis

Pseudomembranous colitis is an inflammation of the colon that occurs most often in people using antibiotics.

Rotavirus

Rotavirus causes severe diarrhea in infants and children. Most cases can be treated at home with extra fluids.

Ruptured spleen

A ruptured spleen is a medical emergency. Immediate surgery is needed to prevent life-threatening bleeding.

Salmonella infection

Salmonella infection will cause only diarrhea and stomach pain in some people, but for infants and immunocompromised people, this bacterial illness can cause life-threatening complications.

Shellfish allergy

Shigella infection

Shigella infection (shigellosis) is a disease that causes diarrhea. Young children are most likely to get the disease, but it can spread to anyone.

Small vessel disease

If you have symptoms of heart disease, but your doctor doesn't see any blocked major arteries, small vessel disease may be the cause.

Tapeworm infection

Tapeworms most commonly enter your body through contaminated food or water. Symptoms aren't always present, but the prognosis is good with prompt diagnosis and treatment.

Testicular torsion

Testicular torsion blocks blood flow to a testicle. Know the signs of this painful condition — and when to see a doctor.

Toxic hepatitis

Toxic hepatitis is liver damage that occurs when your liver isn't able to break down certain toxins — including common pain relievers such as Tylenol.

Traveler's diarrhea

Traveler's diarrhea is unpleasant. Find out how to avoid this travel-related health problem.

Trichinosis

Trichinosis is a roundworm infection you get from eating undercooked, infected pork or other meats. Medications can eliminate the parasite and treat symptoms.

Triple X syndrome

How to identify and treat triple X syndrome.

Typhoid fever

Although rare in industrialized nations, typhoid fever is a serious threat in many parts of the world. Learn how to stay safe when you travel.

Vasculitis

Vasculitis is an inflammation of the blood vessels. It can affect people of any age. Treatment depends on the type of vasculitis.

Whipple's disease

Whipple's disease is a rare bacterial infection that affects primarily the gastrointestinal system, and can be treated successfully with antibiotics.

Wilms' tumor

Wilms' tumor is a rare kidney cancer that primarily affects children.

Zollinger-Ellison syndrome

In Zollinger-Ellison syndrome, tumors in the pancreas or duodenum secrete a hormone called gastrin that leads to excessive stomach acid and ulcers.

Jun. 21, 2013