Lymphocyte Count (from Whole Blood)
This test measures the number of lymphocytes, a type of white blood cell important for fighting infections and maintaining immune function.
["Lymphocytes help protect your body against illness and support long-term immune health."]
Key facts at a glance
- LOINC
- 4662-3
- Short code
- Lymphs+Monos NFr Bld
- Synonyms
- Lymphs+Monos NFr Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Doctors may order a lymphocyte count to diagnose or monitor conditions like infections (e.g., viral or bacterial), immune system disorders (e.g., HIV, autoimmune diseases), or certain cancers (e.g., lymphoma). It can also help assess how your body responds to treatments or identify unusual immune activity.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw a blood sample. It usually takes a few minutes, and you may feel a brief pinch. If you’re nervous, let your healthcare provider know—they can offer tips to make it more comfortable.
What the Test Results Mean
Results are typically reported as a count of lymphocytes per microliter (µL) of blood. While reference ranges vary by lab, lower than expected counts may suggest immune suppression, while higher counts could indicate infection, inflammation, or other conditions. Your doctor will interpret results in the context of your overall health.
Common Conditions Affecting Results
Lymphocyte counts can be affected by infections (e.g., COVID-19, mononucleosis), chronic illnesses (e.g., diabetes, kidney disease), or medications (e.g., steroids, chemotherapy). Stress, illness, or recent vaccinations can also temporarily alter counts.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormally low lymphocyte counts may signal weakened immunity, increasing vulnerability to infections or diseases like HIV/AIDS. Elevated counts can point to overactive immune responses (e.g., allergies, autoimmune reactions) or certain cancers. Regular monitoring is crucial for patients with immune disorders or undergoing treatments that suppress the immune system.
Short name
Lymphocyte Count
Frequently asked questions
How often should I get this test?
Can lifestyle changes affect my lymphocyte count?
What if my results are outside the normal range?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy