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Lymphocyte Count (Absolute)

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of lymphocytes, a type of white blood cell that helps fight infections and supports immune function.

Quick summary

["Lymphocytes help protect your body from illness and infection."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
71597-9
Short code
Lymphocytes NFr.DF Bronch Manual
Synonyms
Lymphocytes NFr.DF Bronch Manual
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
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

Why Is This Test Done?

Doctors may order this test to check for infections, monitor immune function, diagnose conditions like leukemia or lymphoma, or evaluate immune responses to treatments. It can also help assess conditions affecting the bone marrow or lymph nodes.

What Does It Measure?

The test measures the absolute count of lymphocytes in your blood. Lymphocytes are a subset of white blood cells that include B cells, T cells, and natural killer cells, each playing a role in immune defense.

How Is It Performed?

A small sample of blood is taken from a vein, usually in your arm. The blood is then analyzed in a lab to count the lymphocytes. This is typically done using automated blood cell counters or flow cytometry.

What Do Results Mean?

Results are usually reported as a count per microliter (cells/µL). While specific reference ranges can vary by lab, lower than expected counts may suggest immune deficiencies or certain cancers, while higher counts might indicate infections, inflammatory conditions, or other immune responses.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Lymphocyte Count

Frequently asked questions

What Are Common Causes of Abnormal Results?
Low lymphocyte counts can be caused by conditions like HIV/AIDS, certain cancers (e.g., leukemia), autoimmune diseases, or treatments that suppress the immune system (e.g., chemotherapy). High lymphocyte counts may be linked to infections, chronic inflammatory diseases, or certain cancers.
How Often Should I Get This Test?
The frequency depends on your health condition and treatment plan. Your healthcare provider will determine how often you need this test based on your medical history and symptoms.
What Can I Do to Prepare?
No special preparation is usually needed, but avoid heavy meals or strenuous activity before the blood draw. If you’re on medications that affect white blood cells, let your doctor know.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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