Lymphocyte Count (Serum or Plasma)
This test measures the number of lymphocytes, a type of white blood cell that helps fight infections and supports immune function. Lymphocytes include B cells, T cells, and natural killer cells.
["Lymphocytes help protect your body from illness and infection."]
Key facts at a glance
- LOINC
- 108836-8
- Short code
- Lysozyme Msmt SerPl
- Synonyms
- Lysozyme Msmt SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is a Lymphocyte Count Used For?
A lymphocyte count may be checked to evaluate your immune system. It can help diagnose or monitor conditions like infections, autoimmune diseases, or certain cancers. Your doctor might also order this test to assess how well your immune response is working after treatments like chemotherapy.
How Is This Test Done?
A small amount of blood is drawn from a vein in your arm. The blood is then sent to a lab where it is analyzed to count the lymphocytes. No special preparation is usually needed, but you may be asked to avoid certain medications or activities for a short time before the test.
What Does a Lymphocyte Count Tell You?
A lymphocyte count can show whether your immune system is functioning normally. Low levels may indicate immune suppression, infections, or certain diseases, while high levels could suggest overactive immune responses or conditions like chronic inflammation.
When Might You Need This Test?
Your doctor may recommend a lymphocyte count if you have symptoms like frequent infections, unexplained weight loss, fatigue, or if you’re undergoing treatment for a condition that affects the immune system.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Lymphocyte counts can play a key role in diagnosing and managing immune-related disorders. For example, low lymphocyte counts might be seen in HIV/AIDS, certain cancers, or after organ transplants. High counts could be linked to conditions like lupus or certain infections.
Short name
Lymphocyte Level
Frequently asked questions
Why might my doctor order a lymphocyte count?
What are the typical reference ranges for lymphocyte counts?
Can lifestyle changes affect my lymphocyte count?
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