Lymphocyte count (absolute)
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 from illness and support immune health."]
Key facts at a glance
- LOINC
- 30415-4
- Short code
- Lymph Abn NFr Snv
- Synonyms
- Lymph Abn NFr Snv
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
What Is a Lymphocyte Count?
Lymphocytes are a subset of white blood cells that play a key role in immune responses. Your body produces them in the bone marrow and releases them into the bloodstream. This test specifically counts the absolute number of lymphocytes in your blood, which can help doctors assess your immune system’s strength or identify potential issues like infections, autoimmune conditions, or certain cancers.
Why Might You Need This Test?
Doctors may order an absolute lymphocyte count to evaluate immune function, monitor treatment responses (e.g., for cancer or HIV), diagnose infections, or check for conditions like leukemia or lymphoma. It can also help determine if your immune system is too active or too suppressed.
How Is the Test Performed?
This test is typically done using a blood sample drawn from a vein. The blood is analyzed in a lab to count the number of lymphocytes, along with other white blood cells. Results are usually available within a few days.
What Do the Results Mean?
Results are compared to a general reference range for healthy adults, but individual ranges can vary. Low lymphocyte counts may suggest immune deficiencies, infections, or certain medications. High counts could indicate chronic infections, inflammation, or overactive immune responses. Your doctor will interpret results in the context of your overall health and symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low absolute lymphocyte counts can indicate weakened immunity, increasing susceptibility to infections. This may occur in conditions like HIV/AIDS, chemotherapy, or autoimmune diseases. High counts can signal chronic infections (e.g., tuberculosis), certain cancers, or inflammatory disorders. Monitoring lymphocyte levels helps guide treatment decisions, especially in patients undergoing immune-modifying therapies.
Short name
Absolute Lymphocyte Count (ALC)
Frequently asked questions
What causes a low lymphocyte count?
What causes a high lymphocyte count?
Can lifestyle changes affect lymphocyte counts?
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