Table of ContentsView AllTable of ContentsNormal CountsHigh LevelsLow LevelsTreatmentTesting
Table of ContentsView All
View All
Table of Contents
Normal Counts
High Levels
Low Levels
Treatment
Testing
Normal lymphocyte counts are generally between 1,000 and 4,800 cells per microliter of blood in adults and 3,000 to 9,500 cells per microliter in children.
dikushin / Getty Images
Normal Lymphocyte Counts
Lymphocytes are measured in cells per microliter of blood (cells/mL). The total lymphocyte count generally goes down throughout a person’s life.
Normal lymphocyte counts are as follows:
Levels outside the normal range can occur temporarily or indicate a chronic condition. Having too many or too few lymphocytes in your blood can be a sign of infection, autoimmune diseases, and possibly even cancer. Certain medical treatments can also alter your lymphocyte levels temporarily.
Some diseases can cause both lymphocytosis and lymphopenia. For instance, an infection will typically cause lymphocyte counts to increase, but recurrent or severe infections may also cause lymphocyte numbers to plummet.
In other instances, a disease may cause one type of lymphocyte to increase and another type to drop.
High Levels (Lymphocytosis)
Having too many lymphocytes in your blood is called lymphocytosis—an indication that the immune system has been activated in response to a disease or medical condition. Lymphocytosis is defined as a lymphocyte count of:
Lymphocytosis can also persist with chronic (long-term) infections such ashepatitis Borhuman immunodeficiency virus (HIV).
It’s common to see high lymphocyte levels on a blood test. If that’s the case, it’s essential to establish the cause and rule out serious conditions like cancer, often with additional tests and examinations.
Lymphocytosis can indicate cancer of the blood or lymphatic system, such aschronic lymphocytic leukemia(a slow-growing type of blood cancer).
Other possible causes of lymphocytosis include:
Lymphocytosis can lead tolymphadenopathy(swollen lymph nodes) andsplenomegaly(an enlarged spleen). Splenomegaly can cause dull pain in the upper right portion of the body. Other symptoms may develop depending on the underlying cause.
Low Levels (Lymphopenia)
Having too few lymphocytes is calledlymphopenia—an indication that lymphocytes are either being depleted or are not being produced in ample quantities.
Sometimes, lymphopenia can be diagnosed at higher counts as well. A healthcare provider may determine an adult has lymphopenia if they have less than 1,500 cells/mL.
A child age 6 or younger can be diagnosed with lymphopenia if they have less than 2,000 cells/mL.
Low lymphocyte levels may be due to autoimmune diseases, infections, or certain medical treatments. Rare genetic disorders may also interfere with the normal production of lymphocytes.
Possible causes of lymphopenia include:
A low lymphocyte count makes it harder for your body to fight infections. It is important to wash your hands frequently and take other precautions to prevent catching viruses and other communicable illnesses.
Some causes of lymphocytosis or lymphopenia resolve on their own with time, and no treatment is needed.
Blood tests are routinely performed whenever you have signs of an infection and other illnesses. These include tests that measure how many lymphocytes you have in your blood.
The tests are easy to perform and only require a simple blood draw, typically from a vein in your arm.
They include:
B Cells and T CellsThere are two main kinds of lymphocytes: B cells and T cells. They perform different functions in the immune system to protect your body from infection.B-cell lymphocytesrelease antibodies that bind to pathogens or toxins. By doing so, they inactivate the foreign invader or recruit other immune cells that do so.T-cell lymphocytesare key to immune function and can fight cancer or infection. They directly target bacteria and other pathogens, often in response to a B-cell call to action.
B Cells and T Cells
There are two main kinds of lymphocytes: B cells and T cells. They perform different functions in the immune system to protect your body from infection.B-cell lymphocytesrelease antibodies that bind to pathogens or toxins. By doing so, they inactivate the foreign invader or recruit other immune cells that do so.T-cell lymphocytesare key to immune function and can fight cancer or infection. They directly target bacteria and other pathogens, often in response to a B-cell call to action.
There are two main kinds of lymphocytes: B cells and T cells. They perform different functions in the immune system to protect your body from infection.
B-cell lymphocytesrelease antibodies that bind to pathogens or toxins. By doing so, they inactivate the foreign invader or recruit other immune cells that do so.
T-cell lymphocytesare key to immune function and can fight cancer or infection. They directly target bacteria and other pathogens, often in response to a B-cell call to action.
Summary
Lymphocytes are a type of white blood cell. They are produced in the bone marrow and move throughout the lymphatic system to help fight infection and diseases.
Adults usually have a lymphocyte count between 1,000 cells/mL and 4,800 cells/mL, but it’s common to get a blood test result outside of that range. Your healthcare provider will likely suggest further testing to determine the cause.
Having too many lymphocytes (lymphocytosis) or too few lymphocytes (lymphopenia) is commonly a sign of an infection, but may be due to an autoimmune disease, genetic disorder, or cancer.
Certain medical treatments can also affect lymphocyte counts. Treatment focuses on the underlying cause.
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mims MP.Lymphocytosis, lymphocytopenia, hypergammaglobulinemia, and hypogammaglobulinemia.Hematology. 2018:682–90. doi:10.1016/B978-0-323-35762-3.00049-4Devi A, Thielemans L, Ladikou EE, Nandra TK, Chevassut T.Lymphocytosis and chronic lymphocytic leukaemia: investigation and management.Clin Med (Lond). 2022;22(3):225-229. doi:10.7861/clinmed.2022-0150Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).National Heart, Lung, and Blood Institute.Lymphopenia: treatment.MedlinePlus.Complete blood count.University of California, Berkeley.Basic information on flow cytometry.MedlinePlus.B and T cell screen.University of Texas MD Anderson Cancer Center.T cells, B cells and the immune system.
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mims MP.Lymphocytosis, lymphocytopenia, hypergammaglobulinemia, and hypogammaglobulinemia.Hematology. 2018:682–90. doi:10.1016/B978-0-323-35762-3.00049-4Devi A, Thielemans L, Ladikou EE, Nandra TK, Chevassut T.Lymphocytosis and chronic lymphocytic leukaemia: investigation and management.Clin Med (Lond). 2022;22(3):225-229. doi:10.7861/clinmed.2022-0150Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).National Heart, Lung, and Blood Institute.Lymphopenia: treatment.MedlinePlus.Complete blood count.University of California, Berkeley.Basic information on flow cytometry.MedlinePlus.B and T cell screen.University of Texas MD Anderson Cancer Center.T cells, B cells and the immune system.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Mims MP.Lymphocytosis, lymphocytopenia, hypergammaglobulinemia, and hypogammaglobulinemia.Hematology. 2018:682–90. doi:10.1016/B978-0-323-35762-3.00049-4Devi A, Thielemans L, Ladikou EE, Nandra TK, Chevassut T.Lymphocytosis and chronic lymphocytic leukaemia: investigation and management.Clin Med (Lond). 2022;22(3):225-229. doi:10.7861/clinmed.2022-0150Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).National Heart, Lung, and Blood Institute.Lymphopenia: treatment.MedlinePlus.Complete blood count.University of California, Berkeley.Basic information on flow cytometry.MedlinePlus.B and T cell screen.University of Texas MD Anderson Cancer Center.T cells, B cells and the immune system.
Mims MP.Lymphocytosis, lymphocytopenia, hypergammaglobulinemia, and hypogammaglobulinemia.Hematology. 2018:682–90. doi:10.1016/B978-0-323-35762-3.00049-4
Devi A, Thielemans L, Ladikou EE, Nandra TK, Chevassut T.Lymphocytosis and chronic lymphocytic leukaemia: investigation and management.Clin Med (Lond). 2022;22(3):225-229. doi:10.7861/clinmed.2022-0150
Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).
National Heart, Lung, and Blood Institute.Lymphopenia: treatment.
MedlinePlus.Complete blood count.
University of California, Berkeley.Basic information on flow cytometry.
MedlinePlus.B and T cell screen.
University of Texas MD Anderson Cancer Center.T cells, B cells and the immune system.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
