Diseases & conditions A-Z List
Diseases & Conditions A-Z List - «L»:
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Legionnaire's disease
Legionnaire's disease is an acute respiratory infection caused by Legionella bacteria.
Causes
The bacteria that cause Legionnaire's disease have been found in water delivery systems. They can survive in the warm, moist, air conditioning systems of large buildings, including hospitals.
Most cases ar...
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Leiomyosarcoma
A leiomyosarcoma is a rare cancerous tumor of the smooth muscle cells. It is most often found in the uterus or abdomen.
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Leishmaniasis
Leishmaniasis is a parasitic disease spread by the bite of the sandfly.
Causes
There are different forms of leishmaniasis.
Cutaneous leishmaniasis affects the skin and mucus membranes. Skin sores usually start at the site of the sandfly bite. They can last for months or years before healing on the...
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Lepromin skin test
The lepromin skin test is used to determine what type of leprosy a person has.
How the Test is Performed
A sample of inactivated (unable to cause infection) leprosy-causing bacteria is injected just under the skin, usually on the forearm, so that a small lump pushes the skin up. The lump indicates ...
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Leprosy
Leprosy is an infectious disease that has been known since biblical times. It is characterized by disfiguring skin sores, nerve damage, and progressive debilitation.
Causes
Leprosy is caused by the organism Mycobacterium
leprae. It is not very contagious (difficult to transmit) and has a long incub...
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Leptospirosis
Leptospirosis is a rare and severe bacterial infection that occurs when people are exposed to certain environments.
Causes
Leptospirosis is caused by exposure to several types of the Leptospira bacteria, which can be found in fresh water that has been contaminated by animal urine. It occurs in warm...
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Lesch-Nyhan syndrome
Lesch-Nyhan syndrome is an inheritable disorder that affects how the body builds and breaks down purines. Purines are a normal part of human tissue and help make up the body's genetic blueprint. They are also found in many different foods.
Causes
Lesch-Nyhan syndrome is inherited as an X-linked tra...
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Leucine aminopeptidase - blood
Leucine aminopeptidase is a protein, called an enzyme, that is normally found in liver cells.
Serum leucine aminopeptidase is a test that measures how much of this protein is in your blood.
Your urine can also be checked for this protein. See: Leucine aminopeptidase - urine
How the Test is Perform...
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Leucine aminopeptidase - urine
Leucine aminopeptidase is a protein, called an enzyme, that is normally found in liver cells. This article discusses the test to measure how much of this protein appears in your urine.
Your blood can also be checked for this protein. See also: Leucine aminopeptidase - blood
How the Test is Perform...
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Leukemia
Leukemia is a group of cancers that begins in the blood forming cells of the bone marrow.
The term "leukemia" literally means "white blood." White blood cells (leukocytes) are used by the body to fight off infections and other foreign substances. They are made in the bone marrow.
Leukemia leads to...
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Leukemia - resources
The following organizations provide information on leukemia:
National Cancer Institute -- www.cancer.gov/cancertopics/types/leukemia
The Leukemia and Lymphoma Society - www.leukemia.org
Alternative Names
Resources - leukemia...
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Leukemoid reaction
A leukemoid reaction is an increase in white blood cell count similar to what occurs in people with leukemia. However, the reaction is actually due to an infection or another disease and is not a sign of cancer.
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Leukocyte alkaline phosphatase
Leukocyte alkaline phosphatase is a test that tells how much of a protein called alkaline phosphatase (ALP) you have inside your white blood cells. Leukocyte means white blood cell.
See also: Alkaline phosphatase (ALP) test
How the Test is Performed
Blood is typically drawn from a vein, usually fr...
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Leukocyte esterase
Leukocyte esterase is a urine test to look for white blood cells and other signs associated with infection.
How the Test is Performed
A clean catch urine sample is needed. See: Urine specimen - clean catch
How to Prepare for the Test
No special preparation is necessary for this test.
How the Test ...
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Leukoplakia
Leukoplakia is a precancerous sore (lesion) that develops on the tongue or the inside of the cheek in response to chronic irritation. Occasionally, leukoplakia patches develop on the external female genitals.
Causes
Leukoplakia mainly affects the mucus membranes of the mouth. It is caused by irrita...