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Low lymphocyte count in the blood

Blood test
Low lymphocyte count in the blood
Last update: 23/02/2021

What is a low count of lymphocytes in the blood called?

  • Lymphocytopenia
  • Lymphopenia

What is the normal count of lymphocytes in the blood?

If you need to know which are the lymphocytes reference ranges or you require more information about the role of lymphocytes in the blood, you can visit normal lymphocytes count in the blood

What does a low count of lymphocytes in the blood mean?

Lymphocytes play an important role in the immune system because they remove foreign invaders such as bacteria, viruses or parasites. A low lymphocyte count in the blood called lymphocytopenia or lymphopenia increases the risk to suffer an infection.

The reduction of the total lymphocyte count usually correlates to a decrease in the percentage of lymphocytes. Lymphocyte % will be below the 20%. It is better to make the study with the total count of lymphocyte and not with the percentage.

A low lymphocyte count in the blood may be due to numerous reasons. The most common causes are acquired and not hereditary. The most common acquired causes are:

In more than a 25% of the cases, there is not a known reason for a lymphocyte count decrease.

If the reason is hereditary, the main disorders related to lymphocytopenia are Wiskott–Aldrich syndrome, DiGeorge syndrome, Louis–Bar syndrome or cartilage-hair hypoplasia. All of them are rare, but they must be studied in a newborn with lymphocytopenia.

Lymphocytopenia is also common in hospitalized patients, but it is not usually a help for diagnosis.

Lymphocytopenia or a low lymphocyte count in the blood means:

  • Mild lymphocytopenia (0.8 - 1 x 103/µl in adults):

    A mild lymphocytopenia is not a matter for concern. A mild lymphocytopenia is usually considered a benign condition if there is no symptoms. It is probable that in future blood tests the count return to normal range.

    If you are taking medication, it may alter your lymphocyte count. You can ask it to your doctor.

  • Moderate lymphocytopenia (0.5 - 0.8 x 103/µl in adults):

    A moderate lymphocytopenia with no symptom is not a matter to be worried about but requires a follow-up.

    If you feel fatigue or you have a fever, you should visit your doctor.

  • Marked lymphocytopenia (0.2 - 0.5 x 103/µl in adults):

    A marked lymphocytopenia increases the risk to suffer an opportunistic infection such as pneumonia, herpes zoster, or cytomegalovirus infection.

    For that reason, a marked lymphocytopenia requires medical attention. The doctor may perform additional tests to know the cause. He may ask you to follow an HIV test or screening tests to know the function of your kidneys.

  • Severe lymphocytopenia (< 0.2 x 103/µl in adults):

    A severe lymphocytopenia is very dangerous because the risk of suffering a serious infection is very high. The body does not have enough lymphocytes to fight against foreign invaders.

    Therefore, it is necessary to look for urgent medical attention.

Which factors can decrease the lymphocyte count in the blood?

Some particular health situation and many drugs may reduce your lymphocyte count in the blood:

  • Alcohol
  • Zinc deficiency
  • Malnutrition
  • Chemotherapy
  • Radiation therapy
  • Drugs
    • Antineoplastics
      • Asparaginase
      • Cladribine
      • Chlorambucil
      • Fludarabine
      • Chlormethine
      • Methotrexate
    • Antidepressant
      • Bupropion
    • Corticosteroids
      • Prednisone
    • Dimethyl fumarate
    • Immunosuppressive drug
      • Alemtuzumab
      • Rituximab
    • Interferon
    • Niacin
    • Opioid
    • Psychotropic drugs
      • Lithium

Which diseases can decrease your lymphocyte count in the blood?

The following diseases can explain a lymphocyte count in the blood lower than normal:

  • DiGeorge syndrome
  • Louis–Bar syndrome (Ataxia–telangiectasia)
  • Reticular dysgenesis
  • Bruton’s agammaglobulinemia
  • Malaria
  • Cushing's syndrome
  • Sarcoidosis
  • Sepsis
  • Anorexia
  • Intestinal lymphangiectasia
  • Cartilage-hair hypoplasia

What can I do to increase the lymphocyte count in the blood?

You can improve your lymphocyte count if you reduce your alcohol intake. If you take corticosteroid a reduction in the dosages, under medical prescription, may also increase the lymphocyte count.

A low lymphocyte count may increase the risk to suffer an infection. For that reason, you should follow the next tips:

  • Follow a healthy diet
  • Get adequate rest
  • Wash your hand with soap regularly
  • Avoid crowded places
  • Avoid contact with animals

Where can I find more information about lymphocyte count in the blood?

You can visit our pages about:

Which values are considered a low lymphocyte count in the blood?

The following values are considered to be above the normal range:

IMPORTANT: These levels are expressed in number of thousands/µl (microliter). They are an example of a healthy white woman of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

Mild lymphocytopenia
0.9 x103/µl0.8 x103/µl      
Moderate Severe lymphocytopenia
0.7 x103/µl0.6 x103/µl0.5 x103/µl     
Marked lymphocytopenia
0.4 x103/µl0.3 x103/µl0.2 x103/µl     
Severe lymphocytopenia
0.1 x103/µl0 x103/µl      
Medically reviewed by our Medical staff on 23/02/2021


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  • Common Terminology Criteria for Adverse Events (CTCAE). Version 5.0.Published: November 27, 2017. U.S. Department of health and human Services. Available on:

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