| Term |
Synonyms |
Definition |
| L-Thyroxine |
|
The major natural hormone produced by the thyroid gland, given in synthetic form to counter underactivity of the gland. |
| Labia |
Lips |
Commonly refers to the lips of the female external genitalia. |
| Labile diabetes |
Brittle diabetes |
A term used to indicate when a person's blood glucose (sugar) level often swings quickly from high to low and from low to high. |
| Labor |
|
Periodic rhythmical contraction of the uterus which opens the cervix and leads to the birth of a baby. |
| Labyrinth |
|
Portion of the inner ear responsible for balance. |
| Labyrinthitis |
|
An inflammation of the labyrinth that maintains balance; can cause a feeling that one's surroundings are spinning around (known as vertigo) |
| Laceration |
|
Flesh wound caused by tearing. |
| Lacrimal gland |
|
Gland of the eye that secretes tears. |
| Lactagogue |
|
Increases the flow of breast milk in a woman. |
| Lactase |
|
The enzyme that breaks down lactose (the sugar found in dairy products). |
| Lactase deficiency |
|
An inherited disorder in which a person does not have the enzyme lactase, which leads to lactose intolerance, which means the inability to digest lactose |
| Lactation |
|
The production of breast milk. |
| Lactation suppression |
|
A decrease in milk production during pregnancy as a result of high levels of estrogen in the blood. |
| Lactic acid |
|
An acid produced by glucose-burning cells when these cells have an insufficient supply of oxygen. |
| Lactic acidosis |
|
The buildup of lactic acid in the body. The cells make lactic acid when they use glucose (sugar) for energy. If too much lactic acid stays in the body, the balance tips and the person begins to feel ill. The signs of lactic acidosis are deep and rapid breathing, vomiting, and abdominal pain. Lactic acidosis may be caused by diabetic ketoacidosis or liver or kidney disease. |
| Lactose |
|
The sugar found in milk. |
| Lactose intolerance |
|
The inability to break down and absorb the sugar lactose. |
| Lamaze method |
|
A program of physical and emotional preparation of the mother for childbirth. |
| Lamina |
|
Flattened part of the vertebral arch, the ring of bone which, with the vertebral body, surrounds and encloses the spinal cord within that segment of the vertebral column. |
| Laminectomy |
|
A surgical procedure that removes part of a vertebra to relieve pressure on the spinal cord or a nerve branching from the spinal cord. |
| Laminotomy |
|
Surgical shaving of bone from the lamina of a vertebra. |
| Lanceolate |
|
Lance-shaped, oval and pointed at both ends (usually a leaf shape). |
| Lancet |
|
A fine, sharp-pointed blade or needle for pricking the skin. |
| Lanugo |
|
Fine, downy hair appearing on the skin of a fetus. |
| Laparoscope |
|
A viewing instrument used to examine and treat disorders in the abdominal cavity; consists of a long tube with an eyepiece, a lens, and often a camera, which allows the image to be viewed on a monitor. |
| Laparoscopic cholecystectomy |
|
The surgical removal of the gallbladder using a laparoscope. |
| Laparoscopy |
|
Examination of the inside of the abdominal cavity by means of a laparoscope (a viewing instrument) inserted through a small incision. |
| Laparotomy |
|
An operation to open the abdomen. |
| Large cell carcinoma |
|
One of the 4 major types of lung cancer. |
| Large intestine |
|
The part of the digestive tract that is located between the small intestine and the anus. |
| Larvicidal |
|
A substance which kills larvae. |
| Laryngeal |
|
Having to do with the larynx. |
| Laryngectomee |
|
A person who has had his or her voice box removed. |
| Laryngectomy |
|
The surgical removal of all or part of the voice box (larynx) as a treatment for cancer. |
| Laryngitis |
|
An inflammation of the voice box, usually caused by a viral infection; characterized by a hoarse voice. |
| Laryngoscope |
|
A flexible, lighted tube used to examine the larynx. |
| Laryngoscopy |
|
Examination of the larynx with a mirror (indirect laryngoscopy) or with a laryngoscope (direct laryngoscopy). |
| Larynx |
Adams apple |
An organ in the throat used in breathing, swallowing, and talking. It is made of cartilage and muscle and is lined by a mucous membrane similar to the lining of the mouth. Also called the voice box. The larynx has three parts: the supraglottis, the glottis, and the subglottis. Its outer wall of cartilage forms the area of the front of the neck. |
| Laser |
|
A powerful beam of light used in some types of surgery. |
| Laser scanning |
|
A technique using laser beams and camera imaging to scan the body's tissue. |
| Last normal menstrual period |
LNMP |
First day of the last regular, normal menstrual bleeding before conception, which generally takes place, therefore, about 2 weeks into the 40 weeks or 280 days of pregnancy. |
| Latent diabetes |
|
Former term for impaired glucose tolerance. |
| Laser treatment |
|
The use of a laser (a concentrated beam of light) to perform medical procedures, such as the destruction of tumors. |
| Latent infection |
|
An infection that lies dormant in the body for months or years but can reappear. |
| Lateral |
|
The side of the body or body part that is farther from the middle or center (median) of the body. Typically, lateral refers to the outer side of the body part, but it is also used to refer to the side of a body part. For example, when referring to the knee, lateral would mean the side of the knee that is farthest from the opposite knee. The opposite of lateral is medial. |
| Latex |
|
Milky juice produced by plants. |
| Laxative |
|
A substance used to clear feces from the intestines; commonly used to treat constipation. |
| Lazy eye |
|
The common name for the visual defect resulting from untreated strabismus, in which the eyes are not correctly aligned. |
| LDH |
|
Abbreviation for lactic dehydrogenase, a blood test to measure liver function and to detect damage to the heart muscle. |
| LDL cholesterol |
|
Low-density lipoprotein cholesterol provides cholesterol for necessary body functions, but in excessive amounts it tends to accumulate in artery walls; known as "bad" cholesterol. |
| Lead poisoning |
|
Damage to the brain, nerves, red blood cells, or digestive system because of ingestion of lead. |
| Learning disability |
|
Any of a variety of disorders, including hyperactivity, dyslexia, and hearing problems, that can interfere with a person's ability to learn. |
| Left heart failure |
|
A condition in which blood flow to the body is decreased and fluid accumulates due to malfunction of the left ventricle; see Congestive heart failure. |
| Left ventricle |
|
The largest and most muscular chamber of the heart concerned with the pumping of oxygen-rich blood from the lungs (via the left atrium) to all the other tissues of the body, via the aorta. |
| Left ventricular dilatation |
|
Pathological increase in the amount of blood remaining in the left ventricle at the end of contraction. |
| Left ventricular hypertrophy |
|
Pathological increase in the bulk of the muscle in the largest pumping chamber of the heart, which delivers oxygen-rich blood from lungs to aorta. |
| Legionnaires disease |
|
A form of pneumonia that is mainly spread through air-conditioning systems and water. |
| Legume |
|
Beans, peas, and lentils which supply fiber and nutrients and are high in vegetable protein. |
| Leiomyoma |
|
A noncancerous tumor of smooth muscle. |
| Leishmaniasis |
|
A group of parasitic diseases affecting the skin, mucous membranes, and internal organs; transmitted by the bite of a sandfly. |
| Lens |
|
Transparent structure in the eye that focuses the image on the retina. |
| Lente insulin |
|
A type of insulin that is intermediate-acting. |
| Leprosy |
|
A skin infection caused by a bacteria, which can also be associated with nerve damage. The bacteria involved is called Mycobacterium leprae. |
| Leptospirosis |
|
An infection by a spiral-shaped bacterium that affects the skin, eyes, muscles, kidneys, and liver; leptospirosis is carried by rodents. |
| Lesch-Nyhan syndrome |
|
A genetic disorder affecting only men that causes mental handicap, self-mutilation, and aggressive behavior . |
| Lesion |
|
Area of tissue that is injured or diseased such as a wound, abscess, sore, tumor, mole or cyst. |
| Lesser curve |
|
The right side of the stomach from the cardia (entrance at the end of the esophagus or gullet) to the pylorus (exit into the duodenum or beginning of the small bowel). |
| Let Down |
|
The let down reflex is an involuntary reflex during breastfeeding which causes the milk to flow freely. |
| Leucocytes |
|
White blood cells. |
| Leucocytosis |
|
An increase in the number of white blood cells above the normal limit. |
| Leucorrhoea |
|
A white discharge from the vagina. |
| Leukemia |
|
A malignant disease of the blood-forming organs that results in the uncontrolled production of abnormal white blood cells. |
| Leukocyte |
White blood cells |
Cells important in warding off infection. |
| Leukocyte count |
|
The number of white blood cells in the blood, which is used as a measure of health and possible infection. |
| Leukodystrophy |
|
A group of childhood genetic disorders in which the protective coverings of the nerves are destroyed. |
| Leukopenia |
|
An abnormal reduction in the number of leukocytes (white blood cells). |
| Leukoplakia |
|
White patches that can develop in the mouth or on the penis or the opening of the vagina and are potentially cancerous. |
| LH |
|
See Luteinizing hormone. |
| LHRH agonists |
|
Compounds that are similar to LHRH (luteinizing hormone-releasing hormone). |
| Libido |
|
Sexual drive. |
| Lichen planus |
|
A common skin disease in which itchy, small, pink or purple spots appear on the arms or legs. |
| Ligament |
|
Strong fibrous tissue that connects one bone to another. |
| Ligation |
|
The process of closing a blood vessel or duct by tying it off. |
| Ligature |
|
Filament (synthetic or natural) for tying off a structure during surgery. |
| Lightening |
|
The repositioning of a baby lower in the pelvis that usually occurs several weeks before the onset of labor. |
| Ligulet |
|
A narrow projection from the top of a leaf sheath in grasses. |
| Limited joint mobility |
|
A form of arthritis involving the hand; it causes the fingers to curve inward and the skin on the palm to tighten and thicken. This condition mainly affects people with IDDM. |
| Linear accelerator |
|
A machine that creates high-energy radiation to treat cancers, using electricity to form a stream of fast-moving subatomic particles. Also called megavoltage (MeV) linear accelerator or a linac. |
| Linearlipolytic |
|
|
| Lipid |
|
Descriptive term for a fat or fat-like substance found in the blood, such as cholesterol. |
| Lipidosis |
|
Any disorder in which fats cannot be properly broken down by the digestive system. |
| Lipoatrophy |
|
Small dents in the skin that form when injections are repeated too often at the same site. |
| Lipodystrophy |
|
Lumps or small dents in the skin that form when a person keeps injecting the needle in the same spot. Lipodystrophies are harmless. People who want to avoid them can do so by changing (rotating) the places where they inject their insulin. Using purified insulins may also help |
| Lipoma |
|
A noncancerous tumor of fatty tissue. |
| Lipoproteins |
|
Proteins combined with lipids to make them dissolve in blood. |
| Liposarcoma |
|
A cancerous tumor of fatty tissue. |
| Liposuction |
|
Process of removing fat deposits from beneath the skin by using a suction device. |
| Listeriosis |
|
A rare bacterial infection acquired by eating undercooked infected meat or from infected live animals; can be dangerous to newborns and the elderly. |
| Lithiasis |
|
A condition characterized by formation of calculi such as gallstones and kidney stones. |
| Lithotripsy |
|
A procedure done to break up stones in the urinary tract using ultrasonic shock waves, so that the fragments can be easily passed from the body. |
| Lithuria |
|
A morbid condition marked by the presence of excessive amounts of uric acid in the urine. |
| Liver |
|
A large organ in the upper abdomen that is the site of many metabolic functions, including the secretion of bile, the manufacture of proteins, and the storage of glycogen and certain vitamins. |
| Liver failure |
|
The final stage of liver disease, in which liver function becomes so impaired that other areas of the body are affected, most commonly the brain. |
| Lobe |
|
1. A subdivision of an organ, divided by fissures, connective tissue or other natural boundaries. 2. A rounded projecting portion, such as the lobe of the ear. |
| Lobectomy |
|
The surgical removal of a lobe. |
| Lobes |
Lobules, Bulbs |
Each of the breast's 15 to 20 lobes branches into smaller lobules, and each lobule ends in scores of tiny bulbs. The bulbs produce milk which is carried by ducts to the nipple. |
| Local anesthesia |
|
A method of preventing pain by inducing the loss of sensation in a certain area of the body while the patient remains awake. |
| Local recurrence |
|
Redevelopment of a tumor at a site where it had initially been removed. |
| Local therapy |
|
Treatment that affects a tumor and the tissue near it. |
| Lochia |
|
The vaginal discharge in the early weeks following childbirth. |
| Localization biopsy |
|
The use of mammography to locate tissue containing an abnormality that can be detected only on mammograms, so it can be removed for microscopic examination. |
| Locked joint |
|
A joint that cannot be moved because of a disease or a lodged piece of bone or cartilage. |
| Lockjaw |
|
A spasm of the jaw muscles that prevents the mouth from opening, such as that caused by tetanus. |
| Locomotor system |
|
The structures of the body that are responsible for its movement. |
| Lordosis |
|
Exaggerated forward curvature of the lower spine causing swayback. |
| Lou Gehrig's disease |
ALS |
See Amyotrophic lateral sclerosis. |
| Low density lipoprotein |
|
A type of lipoprotein that is the major carrier of cholesterol in the blood, with high levels associated with narrowing of the arteries and heart disease. |
| Low forceps delivery |
|
Childbirth using obstetric forceps applied to the head of the fetus after it has descended into the lower vagina. |
| Low grade |
|
Not acute or vigorous. |
| Lower GI series |
|
A series of x-rays of the colon and rectum that is taken after the patient is given a barium enema. (Barium is a white, chalky substance that outlines the colon and rectum on the x-ray). |
| Low placenta |
Placenta previa |
The location of the placenta in the lower part of the uterus which may partially or completely cover the cervix. |
| Lower uterine segment cesarian section |
Elective eluscs |
Planned delivery of the non labouring pregnant woman by an incision into the narrowed lower third of the uterus, throug either a horizontal or vertical abdominal incision. |
| Lower uterine segment cesarian section, emergency |
|
Unplanned delivery of the non labouring pregnant woman by an incision into the narrowed lower third of the uterus, through either a horizontal or vertical abdominal incision. |
| Lubricant |
|
An oily or slippery substance. A vaginal lubricant may be helpful for women who feel pain during intercourse because of vaginal dryness. |
| Lumbago |
|
A dull, aching pain in the lower back. |
| Lumbar |
|
Pertaining to the lower back. |
| Lumbar puncture |
Spinal tap |
A procedure in which a needle is inserted into the lower region of the spinal canal to take out a sample of spinal fluid or to inject a drug. |
| Lumbar spine |
|
The lower part of the spine between the lowest pair of ribs and the pelvis; made up of five vertebrae. |
| Lumen |
|
The channel within a tubular structure. |
| Lumpectomy |
|
The surgical removal of a section of breast containing cancer. |
| Lung collapse |
|
A condition in which all or part of a lung cannot expand and fill with air. |
| Lung scan |
|
An imaging procedure used to assess blood flow through the lungs. |
| Lungs |
|
The two organs of respiration that bring air and blood into close contact so that oxygen can be added to and carbon dioxide removed from the blood. |
| Lupus erythematosus |
|
A disorder of the immune system that causes inflammation of connective tissue. |
| Luteinizing hormone |
Releasing hormone |
A hormone produced by the pituitary gland that causes the ovaries and testicles to release sex hormones and plays a role in the development of eggs and sperm. |
| Lyme disease |
|
A disease caused by bacteria transmitted through the bite of a tick; characterized by fever, rash, and inflammation of the heart and joints. |
| Lymph |
|
Fluid present in lymphatic vessels. |
| Lymphadenopathy |
|
Swollen lymph nodes. |
| Lymphangiography |
|
An X-ray procedure. |
| Lyphatic |
|
Pertaining to the lymph system. |
| Lyphatic system |
|
A network of vessels that drain lymph back into the blood. |
| Lymph glands |
|
Glands located in the lymph vessels of the body that trap foreign material, including infectious material, and protect the bloodstream from becoming infected. |
| Lymph node |
|
Small structures (from pinhead-size to olive-size) found throughout the body that produce lymphocytes and monocytes, which help protect the body from invasion by bacteria or other organisms. |
| Lymphangiogram |
|
Radiological imaging of the tissue-fluid channels and the accompanying lymph nodes, which drain infection and cancer cells, after the injection of a dye opaque to xrays. |
| Lymphatic system |
|
The tissues and organs that produce, store, and carry cells that fight infection. This system includes the bone marrow, spleen, thymus, lymph nodes, and vessels that carry lymph. |
| Lymphatics |
|
Lymphatics are small thin channels similar to blood vessels. They do not carry blood, but collect and carry tissue fluid from the body to ultimately drain back into the blood stream. |
| Lymphedema |
|
Swelling in the arm caused by excess fluid that collects when the lymph nodes and vessels are removed during surgery or damaged by radiation therapy. The patient's arm and hand become more prone to infection. |
| Lymphnode |
|
Round, oval or bean-shaped aggregation of infection- and cancer-fighting immune cells located along the lymph channels throughout the body. |
| Lymphocytes |
|
White blood cells made in lymphatic tissue and distributed throughout the body by way of the lymphatic fluid and blood. |
| Lymphocytic |
|
Referring to lymphocytes, a type of white blood cell |
| Lymphocytic leukemia |
|
A disease in which white blood cells called lymphocytes divide uncontrollably. |
| Lymphogranuloma venereum |
|
A sexually transmitted chlamydial infection; common in countries with a tropical climate. |
| Lymphoid |
|
Referring to lymphocytes, a type of white blood cell. Also refers to tissue in which lymphocytes develop. |
| Lymphoma |
|
A type of cancer that begins in lymphatic tissue and may spread to other areas of the body. |
| Lymphosarcoma |
|
Another name for a non-Hodgkin's sarcoma; a cancerous tumor in lymphoid tissue. |
| Lysis |
|
Surgical freeing. |
| Lytic |
|
Causing destruction of bone. |