There are several possible causes for a low lymphocyte count, including disease processes and the use of certain medications. Infectious diseases, autoimmune disorders, and some forms of cancer frequently lead to this symptom. The use of steroid medications is sometimes responsible for the development of a lower than normal lymphocyte count. Treatment is focused on proper medical management of the underlying cause of the reduced lymphocyte count.
In many cases, a low lymphocyte count is due to the presence of an infectious disease. Some of the specific diseases that are known to lead to this symptom include AIDS, tuberculosis, and viral hepatitis. Acquired immunodeficiency syndrome, more commonly known as AIDS, is a severe complication of a virus known as HIV that causes destruction of the patient's immune system. Tuberculosis is a bacterial infection that primarily affects the lungs and can be fatal if not properly treated. Viral hepatitis is a form of liver disease that can lead to cancer of the liver, especially if left untreated.
A variety of autoimmune disorders can cause a low lymphocyte count, including lupus, multiple sclerosis, and rheumatoid arthritis. Lupus causes inflammation in various organs of the body and can be fatal in the most severe instances. Multiple sclerosis is a disease that destroys the protective covering of the nerves and can cause varying degrees of physical disability. Rheumatoid arthritis leads to chronic inflammation of the joints and may cause pain and joint deformities.
Cancer, especially forms of cancer that affect the blood, are possible causes of a low lymphocyte count. Leukemia and lymphoma are commonly associated with this symptom. Chemotherapy and radiation therapy are the standard treatment options for these cancers, and the treatments themselves can cause the lymphocyte count to drop even further. Steroid medications are used to treat several types of inflammatory conditions and may cause a temporary decline in the number of lymphocytes in the blood.
The majority of cases involving a low lymphocyte count are not serious and can be successfully treated with antibiotics or other medications. Simple blood tests can detect this condition, often leading to additional testing in order to determine the underlying cause. In many situations, there are no noticeable symptoms, so regular check-ups with a doctor can help to detect any potential problems before serious complications develop.