Hemosiderin is an iron-containing substance that is formed from the hemoglobin of disintegrated red blood cells. Hemosiderin deposition refers to the stain left behind on brain tissue by blood from a brain bleed. Cerebral microbleeds are small chronic brain hemorrhages, likely caused by structural abnormalities of the small vessels in the brain. Extensive research has demonstrated the value of cerebral microbleeds as markers of small-vessel disease (i.e. microvascular ischemic disease). The cause of microvascular ischemic disease is not completely understood, but can be the result of plaque buildup and hardening (atherosclerosis) of the small blood vessels nourishing the brain. This is the same process that can narrow and damage heart blood vessels.

Gynecomastia is a non-cancerous enlargement of male breast gland tissue and is the most common breast condition in males. True gynecomastia should be differentiated from pseudogynecomastia (lipomastia), which refers to an increase in the amount of fat with no increase in breast gland tissue.

The pancreas is a long, flat gland that sits tucked behind the stomach in the upper abdomen. Its main function is to produce enzymes that help with digestion and hormones that help regulate the way the body processes sugar. Although the body and tail of the pancreas are absent, the pancreas has a normal appearance. The absence of the body and tail are reflective of your known history of situs inversus.

Hydroureter refers to dilation of the ureter(s), the narrow tube urine travels down from the kidneys into the bladder. It is most often caused by obstruction of urine outflow due to blockage of the ureter(s) by calculi (stones), chronic inflammation, neoplasia (cancerous or noncancerous growth), or accidental ligation during surgery.Symptoms are variable, but may include pain, either in the side and/or back (known as flank pain), nausea, and/or vomiting. Treatment is based on the cause.

Sometimes because of a weakness in the esophagus (the tube that connects the throat to the stomach) and stomach connection, the stomach can slide up and down into the chest area, which is known as a hiatal hernia. This can allow stomach acid to enter the esophagus more easily, causing acid reflux and heartburn.

Hepatosplenomegaly means that both the liver and the spleen are enlarged. The liver and spleen are connected via the portal vein system. When there is a problem in one organ, it can also cause a problem in the other. The causes for hepatosplenomegaly are varied, and include obesity, infection, anemia, heart failure, cirrhosis, and leukemia/lymphoma (blood cell cancers).

Hepatocellular adenoma is an uncommon, benign (non-cancerous) liver lesion. It has been associated with the use of estrogen-containing medications (e.g. oral contraceptives), anabolic steroids, obesity, metabolic syndrome (e.g. diabetes), and certain genetic syndromes. Hepatic adenomas may be asymptomatic (do not cause symptoms) or may cause symptoms of right upper abdominal pain, nausea, and the sensation of feeling full.

Hepatomegaly means that the liver is enlarged. In adults, the liver normally has a span around 15 cm. The causes for hepatomegaly are varied and include infection, heart failure, cirrhosis and toxin consumption (i.e. alcohol, medication such as Tylenol, and supplements).

Hydroureter refers to dilation of the ureter(s), the narrow tube urine travels down from the kidneys into the bladder. It is most often caused by obstruction of urine outflow due to blockage of the ureter(s) by calculi (stones), chronic inflammation, neoplasia (cancerous or noncancerous growth), or accidental ligation during surgery.Symptoms are variable, but may include pain, either in the side and/or back (known as flank pain), nausea, and/or vomiting. Treatment is based on the cause.

Hydrosalpinx is a common lesion in which the fallopian tube is blocked with a watery fluid due to previous injury or infection (i.e. pelvic inflammatory disease or endometriosis). A hydrosalpinx may be asymptomatic (does not cause symptoms) but may result in chronic pelvic pain or infertility.