What Is Lymphocytosis?

Lymphocytes are special types of white blood cells that form an important part of the body's immune system. The presence of an abnormally high number of lymphocytes in the blood is known medically as lymphocytosis. Although this condition can exist without the presence of disease, it is more commonly caused by factors such as infection, autoimmune disorders, or certain types of cancer. There is no specific treatment for it, as it is more of a symptom than an actual illness. Instead, the treating medical professional will likely order additional tests to find the root cause of the symptom so that the originating illness can be properly treated.

In the majority of cases, lymphocytosis is diagnosed when a medical professional is performing tests due to an illness that is already present. This symptom is rarely found by accident. The combination of various test results along with the diagnosis is often enough to help the healthcare provider to know what is causing the illness. It is possible for the lymphocyte count to be slightly elevated without any disease being present, although many medical professionals will choose to order additional tests to make sure there are no underlying health concerns.

The presence of an infection in the body is a common cause of this condition. Infections may be caused by a fungus, a virus, or bacteria. Prescription medications are often used to treat the infection, although diagnostic testing may be necessary in order to determine the source. This is an important step because treatment options for bacteria will not be useful if a virus is causing the illness, for example.

Autoimmune disorders are another potential cause of lymphocytosis. Medical conditions that compromise the immune system often cause inflammation throughout the body. This chronic inflammation may cause an elevation in lymphocytes as the body attempts to identify and battle foreign invaders. Unfortunately, when an autoimmune disorder is present, this process does not work properly, and the body ends up attacking healthy organs and tissues, leading to further problems.

Certain forms of cancer may lead to this condition as well. This symptom is most common in the types of cancer that affect the blood and the bone marrow. Cancer treatment may or may not help to resolve the elevation. Any questions or concerns about blood test results of an elevation in white blood cells should be discussed with a doctor or other medical professional.