Tumors on your pancreas, called insulinomas, make extra insulin, more than your body can use. This causes blood sugar levels to drop too low. This can cause symptoms of low blood sugar or hypoglycemia.

Interstitial cystitis is an inflamed or irritated bladder wall. It can lead to scarring and stiffening of the bladder. The bladder can’t hold as much urine as it did in the past. It is an ongoing (chronic) disorder.

Interstitial lung disease is the name for a group of more than 200 chronic lung disorders. These diseases inflame or scar the lungs. The inflammation and scarring make it hard to get enough oxygen. The scarring is called pulmonary fibrosis.

Intestinal malrotation is a birth defect. It happens when your baby’s intestinal tract doesn’t form as it should during pregnancy. Malrotation happens when your baby’s intestine doesn’t turn like it should.

If your healthcare provider determines that you have an intestinal obstruction, it means that something is blocking your intestine. Food and stool may not be able to move freely.

An intra-abdominal abscess is a collection of pus or infected fluid that is surrounded by inflamed tissue inside the belly.

Intraventricular hemorrhage (IVH) is bleeding inside or around the ventricles in the brain. The ventricles are the spaces in the brain that contain the cerebral spinal fluid.

Intussusception is a serious problem in the intestine. It occurs when one part of the intestine slides inside another part. The intestine then folds into itself like a telescope. This creates a blockage or obstruction. It stops food that...

Iritis is the inflammation of your iris and the anterior chamber of your eye. Iritis can lead to serious problems. It can cause severe vision loss and even blindness.

Iron deficiency and anemia are common after a gastric bypass or other weight-loss surgery, especially in women. In fact, iron deficiency can occur in more than half of women who are past menopause when they have this surgery.

The most common cause of anemia is a lack of iron. This is called iron deficiency.

Anemia is a common health problem in children. The most common cause of anemia is not getting enough iron. A child who is anemic does not have enough red blood cells or enough hemoglobin.

Irritable bowel syndrome (IBS) is a disorder that affects your large intestine or colon. When you have IBS your colon looks normal. But it does not work the way it should.

Irritable bowel syndrome (IBS) is a long-term (chronic) disorder that affects the large intestine or colon. IBS causes painful belly (abdominal) and bowel symptoms.

Ischemic stroke is the most common type of stroke. It is caused by a blocked artery in the brain. Learn about the risk factors for ischemic stroke and what you can do lower your chances of having one.