Diseases & conditions A-Z List
Diseases & Conditions A-Z List - «H»:
Hymenolepiasis is infestation by one of two species of tapeworm: Hymenolepis nana or Hymenolepis diminuta.
Hymenolepis live in warm climates and are common in the southern United States. The eggs of these worms are ingested by insects.
Humans and other animals become infected when they inten...
Hyperactivity is a state of too much muscle activity. This term is also used to describe a situation when a particular portion of the body is too active, such as when a gland produces too much of its particular hormone.
See also: Attention deficit hyperactivity disorder (ADHD)
Hyperactivity and sugar
Hyperactivity refers to increased movement, impulsiveness, distractibility, and decreased attention span. A popular but controversial belief is that children are more likely to be hyperactive if they eat sugar, artificial sweeteners, or certain food colorings.
This article focuses on the possible co...
Hyperaldosteronism - primary and secondary
Primary and secondary hyperaldosteronism are conditions in which the adrenal gland releases too much of the hormone aldosterone.
Persons with primary hyperaldosteronism have a problem with the adrenal gland that causes it to release too much aldosterone.
In secondary hyperaldosteronism, the ...
Hyperbaric oxygen therapy
Hyperbaric oxygen therapy uses a special chamber, sometimes called a pressure chamber, to increase the amount of oxygen in the blood.
Some, but not very many, hospitals have a hyperbaric chamber. Smaller units may be available in outpatient center.
The air pressure inside a hyperbaric o...
Hypercalcemia is too much calcium in the blood.
Calcium is important to many body functions, including:
Nerve and brain function
Parathyroid hormone (PTH) and vitamin D help manage calcium balance in the body. PTH is made by the parathyroid...
Hypercalcemia - discharge
Your body needs calcium so that you can use your muscles. Calcium also keeps your bones and teeth strong and your heart healthy. Hypercalcemia means you have too much calcium in your blood. Certain kinds of cancers, problems with some glands, and being on bed rest for a long time can cause your bloo...
Hypercoagulable states are conditions that may lead to the abnormal development of blood clots. Blood clots can develop in either arteries or veins.
Blood clots in the legs
Deep venous thrombosis (DVT)
Hepatic vein obstruction (Budd-Chiari syndrome)
Mesenteric vein thrombosis
Hyperelastic skin is skin that can be stretched beyond what is considered normal, and then returns to normal.
Hyperelasticity occurs when there is a problem with the production of collagen fibers. Collagen is a type of protein that makes up much of the body's tissue.
Hyperemesis gravidarum is extreme, persistent nausea and vomiting during pregnancy that may lead to dehydration.
Nearly all women have some nausea or vomiting, or "morning sickness," particularly during the first 3 months of pregnancy. The cause of nausea and vomiting during pregnancy is bel...
Hyperglycemia - infants
Hyperglycemia is abnormally high blood sugar. This article discusses hyperglycemia in infants.
A healthy baby's body usually has very careful control of blood glucose levels. Insulin is the main hormone in the body that regulates glucose. Sick babies may have poor insulin function or low amo...
Hyperhidrosis is a medical condition in which a person sweats excessively and unpredictably. People with hyperhidrosis may sweat even when the temperature is cool or when they are at rest.
Sweating helps the body stay cool. In most cases, it is perfectly natural. People sweat more in warm te...
Hyperimmunization is the presence of a larger-than-normal number of antibodies to a specific antigen. This creates a state of immunity greater than normal. Immune system overactivity can cause many different diseases....
Hyperimmunoglobulin E syndrome
Hyperimmunoglobulin E syndrome is a rare, inherited disease associated with abnormalities of the skin, sinuses, lungs, bones, and teeth.
Hyperimmunoglobulin E syndrome is also know as Job syndrome, after the biblical character Job whose faithfulness was tested by a lifelong affliction of dra...
Hyperkalemia is higher-than-normal levels of potassium in the blood.
Potassium is involved in regulating muscle tissue, and is part of digestion, metabolism, and homeostasis (maintaining a balance between the many electrical and chemical processes of the body).
Hyperkalemia occurs when the l...