Medical Definitions - H
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Hyaline - glassy and translucent.
Hematocrit - the proportion of the blood that consists of packed red blood cells; expressed as a percentage by volume.
Hematoma - an abnormal localized collection of blood in which the blood is usually clotted or partially clotted and is usually situated within an organ or a soft tissue space, such as within a muscle. A hematoma is caused by a break in the wall of a blood vessel. The break may be spontaneous, as in the case of an aneurysm, or caused by trauma.
Hemodialysis - the use of a special machine (a dialysis machine) to filter waste products from the blood and to restore normal constituents to it; most often used for chronic renal disease.
Hemofilter - a part of the ECMO machine that makes hemodialysis possible to help with renal function.
Heparin - an anticoagulant (anti-clotting) medication; a blood thinner.
Hernia - an opening or weakness in the muscular structure of the wall of the abdomen.
Hiatal hernia - weakness and looseness of the muscle ring that holds the junction of the esophagus and stomach in the right place.
High frequency oscillatory ventilation (HFOV) - also known as the oscillator or oscillating vent; a method of mechanical ventilation that employs many short, fast puffs of air to inflate the lungs.
Hirsutism - overabundance of body hair.
Homeostasis - the state of balance in the internal environment of the body achieved by various control mechanisms.
Hydrops - gross edema (swelling), usually with anemia, of the fetus.
Hydronephrosis - the swelling of the kidneys when urine flow is obstructed in any of part of the urinary tract. Hydroureter always accompanies hydronephrosis. Hydronephrosis implies that a ureter and the renal pelvis are overfilled with urine.
Hydroureter - also known as uroureter; the stretching/swelling of the ureter with urine due to blockage.
Hyperal - nutritional substance delivered via IV.
Hypercapnia - also known as hypercarbia; excess of carbon dioxide in the blood.
Hypercarbia - also known as hypercapnia; excess of carbon dioxide in the blood.
hyperdactyly - a congenital physical anomaly consisting of extra fingers or toes.
Hyperlucent lung - the radiographic finding that one lung is less dense than the other normal lung, as from infection or a bronchial foreign body.
Hypernatraemia - the normal concentration of sodium in the blood plasma is 136-145 mM. It is defined as a serum sodium level over 145 mM. Severe hypernatremia, with serum sodium above 152 mM, can result in seizures and death.
Hypokalaemia - a condition of below normal levels of potassium in the blood serum.
Hypoxemia - Insufficient oxygenation of arterial blood.
Hypoxia - Insufficient levels of oxygen in blood or tissue.
Hyaline membrane disease - type of respiratory distress syndrome of the newborn in which there is formation of a hyaline-like membrane lining the terminal respiratory passages; extensive atelectasis is attributed to lack of surfactant.