Lymphopenia: Low Lymphocyte Count, Causes, Symptoms and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Lymphopenia means having a lower-than-normal level of lymphocytes, a type of white blood cell that helps protect the body from infection. A low lymphocyte count can increase the chance of getting sick, but mild lymphopenia may cause no symptoms and may not require treatment. [1]
If you have an infection, frequent or long-lasting infections, or a condition that may make you more likely to get infections, contact a qualified healthcare provider.
Medical note: This article is educational and does not diagnose or treat an individual. A qualified clinician should confirm any diagnosis, testing plan or treatment decision.
Quick Answer
Lymphopenia is a lower-than-normal number of lymphocytes in the blood. Lymphocytes are white blood cells that help the body fight infection. Lymphopenia can be acute and resolve after an illness or chronic and require ongoing care. It is not cancer, although some cancers and cancer treatments can cause a low lymphocyte count. [1]
What the research says
Low lymphocyte counts on admission have been linked to worse outcomes in COVID-19. A meta-analysis of 24 studies (3,099 patients) found that lymphopenia was associated with severe COVID-19 (odds ratio 3.70, 95% CI 2.44–5.63), and patients who died had lymphocyte counts about 395 cells per microliter lower on average than those who survived (Huang & Pranata, J Intensive Care, 2020). [2]
Poor nutrition can contribute to a low lymphocyte count. In a prospective study of 101 hospitalized patients with COVID-19, 58.4% had a low total lymphocyte count, and malnutrition was an independent risk factor for it (odds ratio 3.05, 95% CI 1.5–6.19) (Zhang et al., Front Nutr, 2022). [3]
What do lymphocytes do?
Lymphocytes are white blood cells that help the body fight germs, including viruses, bacteria, parasites and fungi. They also help destroy abnormal cells, such as cancer cells. About 20% to 40% of white blood cells are lymphocytes. [1]
There are three main types of lymphocytes: T lymphocytes, also called T-cells; B lymphocytes, also called B-cells; and natural killer cells, often called NK cells. To see how these cells fit into the body’s wider defenses, read our guide to the human immune system. [1]
Lymphocyte type | Also called | What to know |
T lymphocytes | ||
T-cells | ||
One of the three main types of lymphocytes | ||
B lymphocytes | ||
B-cells | ||
One of the three main types of lymphocytes | ||
Natural killer cells | ||
NK cells | ||
One of the three main types of lymphocytes |
Lymphopenia is also called lymphocytopenia or lymphocytic leukopenia. Leukopenia means having a low white-blood-cell count; lymphocytic leukopenia means that the low count specifically involves lymphocytes. [1]
What are normal lymphocyte levels?
Normal lymphocyte levels differ between adults and children.
Group | Normal range | Level described as lymphopenia |
Adults | ||
1,000–4,800 lymphocytes per microliter of blood | ||
Less than 1,000 per microliter | ||
Children | ||
3,000–9,500 lymphocytes per microliter of blood | ||
Depends on age | ||
Children under 2 years | ||
Age-specific range | ||
Less than 3,000 per microliter |
A single low result does not explain why the level is low. A qualified provider interprets the result alongside symptoms, medical history, medicines, recent illnesses and other test findings.
What are the symptoms of lymphopenia?
Lymphopenia itself does not cause symptoms. Instead, an underlying condition associated with lymphopenia may cause symptoms. [1]
Possible symptoms include fever, cough, runny nose, rash or other skin irritation, swollen lymph nodes, swollen joints, mouth ulcers, jaundice and an enlarged spleen. With severe lymphopenia, infections may occur frequently or last a long time. With mild lymphopenia, a person may have no symptoms. [1]
Pattern | What may happen |
Mild lymphopenia | No symptoms may occur |
Severe lymphopenia | Frequent infections or infections that last a long time may occur |
Associated illness | Fever, cough, runny nose, rash, swollen lymph nodes, swollen joints, mouth ulcers, jaundice or enlarged spleen may occur |
When should you see a healthcare provider?
See a qualified healthcare provider if you have an infection, frequent or long-lasting infections, or a condition that makes you more susceptible to infections. Ask which signs and symptoms should prompt medical care.
What causes lymphopenia?
Lymphopenia can be present from birth or develop over time. It may be acute, meaning it resolves with treatment or on its own, or chronic, meaning it may require lifelong treatment. [1]
The most common causes are infections, medications and nutritional deficiencies. Other causes include inherited conditions, autoimmune diseases, blood disorders, cancer, treatment side effects and excessive alcohol use. [1]
Cause category | Examples |
Infections | HIV/AIDS, influenza, COVID-19, hepatitis, malaria, measles, pneumonia and tuberculosis; viruses, bacteria, parasites and fungi may cause infections linked to lymphopenia |
Nutritional deficiencies | Not enough protein, vitamin B12, folic acid or zinc; this is described as the most common cause worldwide |
Inherited conditions | Ataxia-telangiectasia, common variable immunodeficiency, DiGeorge syndrome, SCID and Wiskott-Aldrich syndrome |
Autoimmune diseases | Lupus, sarcoidosis, myasthenia gravis and rheumatoid arthritis |
Blood disorders and cancer | Aplastic anemia, lymphoma, leukemia and myelodysplastic syndromes |
Medication or treatment effects | Bone-marrow transplant, chemotherapy, radiation therapy and immunosuppressants including corticosteroids |
Alcohol toxicity | Excessive alcohol use |
Is lymphopenia cancer?
No. Lymphopenia is not cancer. However, cancer can cause lymphopenia if it interferes with the body’s ability to make lymphocytes. Some cancer treatments can also temporarily lower lymphocyte levels. [1]
How is lymphopenia diagnosed?
A healthcare provider reviews your medical history and symptoms, asks about lifestyle and performs a physical examination. The provider may look for signs of infection, such as fever, swollen lymph nodes or an enlarged spleen. Questions about diet may help identify nutritional deficiencies, and questions about sexual health may help evaluate infectious causes such as HIV. [1]
Evaluation or test | What it may assess |
Medical history | Past and present conditions, medicines, treatments and recent infections |
Physical examination | Signs of infection, fever, swollen lymph nodes or an enlarged spleen |
Lifestyle questions | Diet, safer-sex practices and other possible causes |
Complete blood count (CBC) | The number of blood cells, including white blood cells |
CBC with differential | The number of individual white-blood-cell types, including lymphocytes |
Flow cytometry | The different types of lymphocytes, including B-cells, T-cells and NK cells |
Immunoglobulin level test | The amount of antibodies in the blood |
Bone-marrow analysis | Problems with blood-cell production |
Condition-specific tests | Tests for HIV, tuberculosis, flu, COVID-19 and other related conditions |
A low lymphocyte count is a finding, not a complete explanation. The provider uses test results and the wider clinical picture to look for the underlying cause.
How is lymphopenia treated?
Treatment depends on the cause and symptoms. Mild lymphopenia without symptoms may not require treatment, and lymphocyte levels may return to normal after the body recovers from an infection. When another condition is responsible, treatment focuses on that underlying condition. [1]
For some inherited conditions that prevent the body from making enough lymphocytes, a hematopoietic stem-cell transplant may be a potential cure. This is a complex procedure with risks, and it is not suitable for everyone. [1]
People with severe lymphopenia may need immunoglobulin shots, also called IG shots, to strengthen the immune system and help prevent frequent infections. A qualified provider decides whether this treatment is appropriate. [1]
What is the outlook for lymphopenia?
The outlook depends on what is causing the low lymphocyte level. Lymphocytes often return to normal after recovery from an infection. If a more serious condition causes lymphopenia, treatment may be longer and more involved. [1]
Some people have acute lymphopenia that resolves, while others have chronic lymphopenia that requires ongoing care. Your provider can explain what follow-up is needed based on the cause and test results.
Can lymphopenia be prevented?
Lymphopenia caused by an inherited condition cannot be prevented. You can reduce the risk of acquired lymphopenia by taking precautions against germs, practicing safer sex to reduce the risk of infections such as HIV, and drinking alcohol in moderation. Moderation means no more than one can of beer, one glass of wine or one shot of liquor per day. [1]
If you have lymphopenia, infection-prevention steps include:
Getting vaccinated against flu and COVID-19. [1]
Avoiding people who are or may be sick, and avoiding crowded indoor areas. [1]
Washing your hands regularly with soap and water or using an alcohol-based hand sanitizer. [1]
Wearing a mask around airborne viruses. [1]
Cooking food to the appropriate temperature and washing fruits and vegetables thoroughly. [1]
Avoiding activities where cuts or scrapes are more likely. [1]
Ask a qualified healthcare provider about extra precautions that may apply to your situation.
Conclusion: low lymphocytes have many possible causes
Lymphopenia means having fewer lymphocytes than expected in the blood. It can be mild and symptom-free or severe enough to contribute to frequent or long-lasting infections. Possible causes range from infections and nutritional deficiencies to inherited conditions, autoimmune diseases, blood disorders, cancer, treatment effects and excessive alcohol use.
Diagnosis may include a CBC, CBC with differential, flow cytometry, immunoglobulin testing, bone-marrow analysis and tests for related conditions. Treatment depends on the cause and may not be necessary in mild cases.
If you have an infection, repeated infections or concerns about a low lymphocyte count, contact a qualified healthcare provider for evaluation. Rinnit.com is here to make complex health information easier to understand.
Frequently Asked Questions
What does lymphopenia mean?
Lymphopenia means having a lower-than-normal level of lymphocytes in the blood. Lymphocytes are white blood cells that help protect the body from infection.
What is a normal lymphocyte count for adults?
The adult normal range is 1,000 to 4,800 lymphocytes per microliter of blood. Adult lymphopenia is fewer than 1,000 lymphocytes per microliter.
Can lymphopenia cause symptoms?
Lymphopenia itself does not cause symptoms. An associated condition may cause fever, cough, runny nose, rash, swollen lymph nodes, swollen joints, mouth ulcers, jaundice or an enlarged spleen. Severe lymphopenia may be linked to frequent or long-lasting infections.
Is lymphopenia the same as a low white-blood-cell count?
Not exactly. Leukopenia means a low white-blood-cell count in general. Lymphocytic leukopenia refers specifically to a low number of lymphocytes.
What causes a low lymphocyte count?
Possible causes include infections, nutritional deficiencies, inherited conditions, autoimmune diseases, blood disorders, cancer, medication or treatment effects and excessive alcohol use.
How is lymphopenia diagnosed?
Diagnosis may involve a medical history, physical exam, CBC, CBC with differential, flow cytometry, immunoglobulin levels, bone-marrow analysis and tests for related infections or conditions.
Does lymphopenia always need treatment?
No. Mild lymphopenia without symptoms may not require treatment, and levels may return to normal after recovery from an infection. Treatment is based on the cause and symptoms.
How can I reduce infection risk with lymphopenia?
Steps include vaccination for flu and COVID-19, avoiding sick people and crowded indoor areas, hand hygiene, masking around airborne viruses, safe food preparation, washing produce and avoiding activities that could cause cuts or scrapes. Ask a provider about extra precautions.
When should I see a provider?
See a healthcare provider if you have an infection or a condition that makes you more susceptible to infections. Ask which symptoms should alert you to seek medical care.
Is lymphopenia a sign of cancer?
Usually not. Lymphopenia itself is not cancer, and infections, medicines and poor nutrition are more common causes. Some blood cancers and cancer treatments can lower lymphocytes, so your provider will look for the cause.
Related Reading
CD4 Count: Normal Range, What a Low CD4 Count Means and How Often It's Checked explains the blood test that tracks helper T cells and immune strength.
References
Cleveland Clinic. Lymphopenia: Symptoms, Causes & Treatment. Cleveland Clinic. Last updated March 15, 2023. https://my.clevelandclinic.org/health/diseases/24837-lymphopenia
Huang I, Pranata R. Lymphopenia in severe coronavirus disease-2019 (COVID-19): systematic review and meta-analysis. J Intensive Care. 2020;8:36. PMID 32483488. https://doi.org/10.1186/s40560-020-00453-4
Zhang K, Qin W, Zheng Y, et al. Malnutrition contributes to low lymphocyte count in early-stage coronavirus disease-2019. Front Nutr. 2022;8:739216. PMID 35071291. https://doi.org/10.3389/fnut.2021.739216
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare professional with any questions about a medical condition or treatment.
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