lymphocytopenia

medical condition

Also known as: lymphopenia

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Last updated

July 21, 2026

Quick Summary

Lymphocytopenia, also known as lymphopenia, is a medical condition characterized by an abnormally low number of lymphocytes, a type of white blood cell crucial for the immune system. These cells, including B cells and T cells, originate in the bone marrow and play a vital role in identifying and neutralizing foreign substances like bacteria and viruses.1

A low lymphocyte count, often detected through a complete blood count (CBC) test, can be indicative of various underlying issues. These can range from malnutrition and certain infections to rare inherited disorders and autoimmune conditions. Leukopenia, a broader term for a low white blood cell count, can also accompany lymphocytopenia and may be caused by infections, certain medications, or other chronic health problems.12

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lymphocyte
Lymphocyte counts
…children, may be indicative of lymphocytopenia (lymphopenia), whereas those above it are a sign of lymphocytosis. Lymphocytopenia is associated with a variety of conditions, ranging from malnutrition to rare inherited disorders such as ataxia-telangiectasia or severe combined immunodeficiency syndrome. Lymphocytosis typically is associated with infections, such as mononucleosis or whooping…
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…children, may be indicative of lymphocytopenia (lymphopenia), whereas those above it are a sign of lymphocytosis. Lymphocytopenia is associated with a variety of conditions, ranging from malnutrition to rare inherited disorders such as ataxia-telangiectasia or severe combined immunodeficiency syndrome. Lymphocytosis typically is associated with infections, such as mononucleosis or whooping…
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