Dictionary

hematuria, gross Blood in the urine that can be seen with the naked eye. Hematuria may or may not be accompanied by pain, but it is always abnormal and should be further investigated.

hematuria See blood in the urine.

hematopoiesis The production of all types of blood cells including formation, development, and differentiation of blood cells. Prenatally, hematopoiesis occurs in the yolk sack, then in the liver, and lastly in the bone marrow. In the normal situation, hematopoiesis in adults occurs in the bone marrow and lymphatic tissues. All types of blood cells are…

hematoma, subdural A hematoma between the brain and its covering, the dura. If the hematoma causes increased pressure on the brain, neurological abnormalities including slurred speech, impaired gait, and dizziness may result and progress to coma and even death. Subdural hematomas can be caused by minor accidents to the head, major trauma, or the spontaneous…

hematoma, subcutaneous A hematoma beneath the skin.

hematoma, intracranial A hematoma within the brain cavity (cranium). The hematoma may or may not be within the brain itself. Treatment can require surgical drainage and depends on the location, size, and duration of the hematoma. See also hematoma, epidural; hematoma, intracerebral; hematoma, subdural.

hematoma, intracerebral A hematoma within the brain itself. Diagnosis is usually made by CT or MRI scan. Treatment involves surgery.

hematoma, epidural A hematoma between the skull and the brain’s tissue-like covering, which is known as the dura. Epidural hematoma is usually caused by a full-on blow to the head and is often associated with skull fracture. Diagnosis is usually made via MRI or CT scan. Treatment is trepanation: drilling through the skull to drain…

hematoma A localized swelling that is filled with blood caused by a break in the wall of a blood vessel. The breakage may be spontaneous, as in the case of an aneurysm, or caused by trauma. The blood is usually clotted or partially clotted, and it exists within an organ or in a soft tissue…

hematology The branch of medicine concerned with the blood and blood-forming tissues, encompassing the diagnosis and treatment of disorders of the coagulation process, blood-cell formation, hemoglobin synthesis, and immune system, as well as cancers of blood and blood-forming organs such as leukemias and lymphomas.

hematologist A physician who specializes in diagnosing and treating diseases of the blood.

hematocrit The proportion of the blood that consists of red blood cells. Abbreviated Hct. Hct is expressed as a percentage. For example, an Hct of 25 percent means that there are 25 milliliters of red blood cells in 100 milliliters of blood. The normal ranges for Hct depend on the age and, after adolescence, the…