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Lymphocyte Count (Fluid Sample, Manual Counting)

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

This test measures the number of lymphocytes, a type of white blood cell, in your blood or body fluid. Lymphocytes help fight infections and are part of your immune system.

Quick summary

["Lymphocytes help protect your body from infections and diseases."]

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

Key facts at a glance

LOINC
66761-8
Short code
Lymphocytes NFr Dial fld Manual
Synonyms
Lymphocytes NFr Dial fld 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

What Is a Lymphocyte Count Used For?

A lymphocyte count helps doctors assess your immune system. It may be used to diagnose conditions like infections, autoimmune diseases, or certain cancers. It can also help monitor treatment progress or check for immune system changes over time.

How Is This Test Done?

Blood or body fluid is collected via a simple blood draw or other sample collection method. The sample is then examined under a microscope or counted manually to determine the lymphocyte count.

Why Might You Need This Test?

You might need a lymphocyte count if you have symptoms like frequent infections, fatigue, or unexplained weight loss. Doctors may also order it to check immune function before treatments like chemotherapy or to monitor conditions like HIV or lymphoma.

What Are Possible Results?

Results are expressed as a count of lymphocytes per microliter (µL) of blood or fluid. While specific reference ranges vary by lab, lower or higher than expected counts may signal health concerns.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lymphocyte Count

Frequently asked questions

How often should I expect this test?
The frequency depends on your health condition and treatment plan. Your doctor will determine if repeat tests are needed, often based on symptoms or monitoring progress.
What can affect my lymphocyte count?
Several factors can influence lymphocyte counts, including infections, medications (like steroids), chronic illnesses, or stress. Diet, sleep, and overall health also play a role.
Do I need to prepare for this test?
Generally, no special preparation is needed. However, avoid strenuous activity or certain medications (like blood pressure drugs) before the test if instructed by your doctor.
  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