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Lymphocyte Count (Peripheral Blood)

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

["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
95220-0
Short code
Lymphocytes NFr Stem prod Manual
Synonyms
Lymphocytes NFr Stem prod 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 This Test Might Be Ordered

Your doctor may order this test to check for signs of immune system issues, such as infections, autoimmune diseases, or conditions like leukemia. It can also help monitor treatment responses in certain illnesses.

What to Expect Before the Test

No special preparation is needed for this test. You’ll have a small needle inserted into your arm or hand to draw a blood sample. The process is quick and usually painless.

What the Results Mean

Results show the count of lymphocytes in your blood. While reference ranges vary by lab, low counts may suggest immune problems, while high counts could indicate infection, inflammation, or other conditions.

Common Conditions Affecting Results

Lymphocyte counts can be affected by infections (like colds or flu), chronic illnesses (such as HIV or lupus), or certain medications. Stress, diet, and even time of day can also influence results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Lymphocyte counts are crucial for diagnosing and managing immune-related disorders. Low counts may prompt further testing for conditions like immunodeficiency, while high counts can signal acute infections or chronic diseases requiring treatment adjustments.

Short name

Lymphocyte Count

Frequently asked questions

How often should I get this test?
The frequency depends on your health condition. If you have a chronic illness or are under treatment, your doctor may recommend regular monitoring. Otherwise, it’s often done as needed for symptoms or diagnostic purposes.
What does a normal range mean for me?
A normal range doesn’t mean your immune system is perfectly healthy—it just means your lymphocyte count falls within the typical lab-defined limits. Your doctor will interpret results in the context of your overall health.
Can lifestyle changes affect my lymphocyte count?
Yes, diet, stress, sleep, and exercise can influence white blood cell counts. Avoiding infections, managing stress, and maintaining good hygiene may help support your immune system.
  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