Enter a word or phrase below to search our online dictionary of over 1,300 general medical terms, or click on a letter of the alphabet to view all terms beginning with that letter:
Search for 'L'
| Phrase | Definition |
|---|---|
| labia | Lip-shaped structures; often used to describe the outer folds of the female genitalia. |
| labyrinth | The system of interconnecting canals and cavities in the inner ear. Plays an important role in hearing and in balance. |
| laceration | A wound caused by a cut from a sharp instrument or the tearing of body tissue. |
| lacrimation | Discharge of tears. "Watering" eyes. |
| lactase | An enzyme that converts the milk sugar lactose into glucose and galactose. |
| lactation | Secretion of milk by the breasts. |
| lactose | Milk sugar. |
| laryngitis | Inflammation of the larynx, resulting in a temporary loss of voice. |
| larynx | The voice box. |
| lateral | Toward the side, sideways. |
| lavage | Washing out of an organ, especially the stomach. |
| Legg-Calve-Perthes disease | Perthes disease A disease in which the blood supply to the femur is reduced, causing the bone to collapse. |
| lens | 1. A curved glass used to bring together or spread rays of light. 2. The transparent organ lying behind the iris and pupil that focuses light on the retina of the eye. |
| leprosy | A progressive infectious disease that attacks the skin, flesh and nerves; characterized by nodules, ulcers, scaly scabs, deformities and the eventual loss of sensation. Also called Hansen's disease. |
| lesion | Any damage to a tissue. Marks, spots, moles or other problems of the skin. |
| lethargy | A lack of energy; sluggishness, dullness or apathy. |
| leukemia | Cancer of the tissues in the bone marrow, spleen and lymph nodes. |
| leukocytes | White blood cells, the blood cells responsible for fighting infection. |
| leukopenia | A lower than normal number of leukocytes in the blood. |
| leukopheresis | Selective removal of the white blood cells from a donor's blood. The other components of the blood are then returned to the donor. |
| leukoplakia | Thick, white patches in the mouth that may become malignant. |
| lichen | Any of various skin diseases characterized by sores and enlarged skin markings. |
| ligament | A tough band of connective tissue connecting bones or holding organs in place. |
| ligature | A wire or thread used to tie off blood vessels or to close incisions or wounds. |
| lightening | The feeling of decreased abdominal pressure during the last few weeks of pregnancy caused by the uterus dropping into the pelvis. |
| limbus | Margin, or border. The margin of the cornea where it contacts the sclera. |
| lingua | Tongue. |
| lipid | Cholesterol, triglycerides and related substances. |
| lipocyte | A fat cell. |
| lipolysis | The splitting up, or destruction, of fat. |
| lipoma | Fatty tumor. |
| lipoprotein | Any of a group of proteins combined with a lipid that allow lipids to be transported in the circulatory system. |
| liposuction | A surgical procedure that changes body shape by removing fat cells. |
| litholysis | Breaking up of a stone, such as a gallstone. |
| lithotripsy | A procedure to break up kidney stones into smaller pieces that can more easily pass out of the body. |
| liver | The large organ in the upper right abdomen that functions in digestion and storage of food, disposal of worn-out red blood cells and detoxification of the body. |
| lobe | 1. The fleshy lower part of the ear. 2. A well-defined portion of an organ. |
| lobectomy | Surgical removal of the lobe of an organ. |
| lobotomy | A surgical operation in which a lobe of the brain, especially the frontal lobe of the cerebrum, is cut into or across. This used to be a common procedure to calm selected psychotic patients before the development of modern tranquilizers. |
| lochia | The discharge from the vagina that occurs for several days to weeks after childbirth. |
| lockjaw | Tetanus infection. |
| loins | The portion of the back between the rib cage and pelvis. |
| lordosis | Forward curvature of the spine, producing a hollow in the back. |
| LSD | Lysergic acid diethylamide. A hallucinogenic drug. |
| lumbago | Pain in the lower back. |
| lumbar | Having to do with the lower back, the loins. |
| lungs | The main respiratory organs in the chest where blood is oxygenated. |
| lupus erythematosus | A usually chronic inflammatory disease that causes abnormalities of blood vessels and connective tissue in various parts of the body. |
| luteinizing hormone | A hormone secreted by the anterior pituitary gland, responsible for stimulating ovulation in the female and testosterone production in the male. |
| Lyme disease | A disease spread by deer ticks characterized at first by a skin rash, headache and fever, and later by arthritis and heart damage. |
| lymph | Consists primarily of a clear, yellowish fluid and white blood cells. Found in the lymphatic system. |
| lymph node | Any of many small, compact structures lying in groups along the course of the lymphatic vessels and producing lymphocytes. |
| lymphadenitis | Inflammation of the lymph nodes. |
| lymphangitis | Inflammation of a lymphatic vessel. |
| lymphatic system | The vessels and structures involved in carrying lymph from the tissues to the blood. |
| lymphedema | Swelling of tissue because of the buildup of too much lymph fluid. |
| lymphocyte | A type of leukocyte (white blood cell) involved in the production of antibodies and the development of immunity. |
| lymphoma | A malignant tumor of the lymphoid tissues. |
