Key Points

• Lymphocytopenia is a condition in which your blood has a low number of white blood cells called lymphocytes.
• Lymphocytes help protect your body from infection. When your blood has a low number of lymphocytes, you have an increased risk for infection.
• A normal lymphocyte count for adults usually is between 1,000 and 4,800 lymphocytes per microliter of blood. For children, a normal count usually is between 3,000 and 9,500 lymphocytes per microliter of blood.
• A count of less than 1,000 lymphocytes per microliter of blood in adults or less than 3,000 lymphocytes per microliter of blood in children is lower than normal.
• In general, a low lymphocyte count develops for one or more of these reasons:
  • The body doesn't make enough lymphocytes.
  • The body makes enough lymphocytes, but they are destroyed due to an abnormal condition.
  • The lymphocytes get stuck in the spleen or lymph nodes.
• A number of diseases, conditions, and factors can cause the problems that lead to lymphocytopenia. These conditions can be inherited or acquired. The inherited conditions are rare. A common acquired cause of lymphocytopenia is AIDS.
• Lymphocytopenia alone may not cause any signs or symptoms. The condition usually is found when a person is tested for other diseases or conditions, such as AIDS. If you have unusual infections, repeat infections, and/or infections that won’t go away, your doctor may suspect that you have lymphocytopenia.
• Your doctor will diagnose lymphocytopenia based on your medical history, a physical exam, and tests results.
• Treatment for lymphocytopenia depends on its cause and severity. Mild lymphocytopenia with no underlying cause may not require treatment. If you have unusual infections, repeat infections, and/or infections that won't go away due to lymphocytopenia, you'll need treatment for the infections.
• You can't prevent lymphocytopenia that's due to an inherited cause. You may be able to lower your risk for acquired lymphocytopenia by lowering your risk for the conditions that cause it.
• The main risk of lymphocytopenia is infections. If you have lymphocytopenia, take steps to prevent infections and report any signs of infection to your doctor right away. Fever is the most common sign of infection.