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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, in your blood. Lymphocytes help fight infections and are part of your immune system.

Quick summary

["Knowing your lymphocyte count can help doctors assess your immune health and response to treatments."]

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

Key facts at a glance

LOINC
61118-6
Short code
Lymphocytes.cyIgG/lymph NFr Fld
Synonyms
Lymphocytes.cyIgG/lymph NFr Fld
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
86430
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 This Test Is Done

Doctors may order an absolute lymphocyte count to evaluate your immune system function. It can be used to monitor conditions like infections, immune deficiencies, or responses to treatments such as chemotherapy or immune-modulating therapies.

What to Expect Before the Test

This test is typically done using a simple blood draw from a vein in your arm. No special preparation is needed, but inform your healthcare provider about any medications or conditions that could affect results.

What the Results Mean

Results are usually reported as a count of lymphocytes per microliter (cells/µL) of blood. Lower counts may indicate immune suppression, while higher counts could suggest certain infections or inflammatory conditions. Your doctor will interpret results in the context of your overall health and symptoms.

Common Conditions Monitored

This test helps diagnose or monitor conditions such as HIV/AIDS, certain cancers (like leukemia), autoimmune diseases, or after organ transplants. It can also guide decisions about starting or adjusting treatments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Abnormally low lymphocyte counts can signal weakened immunity, increasing susceptibility to infections. High counts may reflect chronic infections, inflammation, or certain immune disorders. Regular monitoring is key for patients undergoing treatments that suppress the immune system.

Short name

Absolute Lymphocyte Count

Frequently asked questions

What causes a low lymphocyte count?
Low lymphocyte counts can result from infections (like HIV), certain medications (e.g., chemotherapy), autoimmune diseases, or conditions that drain your immune system, such as severe malnutrition or chronic stress.
What causes a high lymphocyte count?
High lymphocyte counts may occur with infections (e.g., viral or bacterial), certain cancers (like lymphoma), or inflammatory diseases. Stress, sleep deprivation, or certain medications can also temporarily raise counts.
How often should I get this test?
Your doctor will determine the frequency based on your health condition, treatment plan, or symptoms. Follow-up tests may be scheduled periodically, especially if you’re undergoing treatments that affect immunity.
  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