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Lymphocyte Count in Whole Blood

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

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

Quick summary

["Lymphocytes help protect your body by identifying and attacking harmful invaders like bacteria and viruses."]

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

Key facts at a glance

LOINC
46238-2
Short code
Lymphs Kappa/lymph NFr Fld
Synonyms
Lymphs Kappa/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

Your healthcare provider may order this test to evaluate your immune system, check for infections, monitor conditions like leukemia, or assess responses to treatments. It can also help diagnose or monitor autoimmune diseases or certain types of cancers.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast before the test if it’s part of a larger blood draw, but this is not always the case for lymphocyte counts alone. Bring any medications or questions to your appointment.

During the Test

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are typically reported as a count of lymphocytes per microliter (µL) of blood. While reference ranges can vary by lab, lower than expected counts may indicate immune suppression, infections, or certain blood disorders, while higher counts might suggest inflammation, infections, or certain immune-related conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Lymphocyte counts are critical for diagnosing and managing immune-related conditions. Low lymphocyte counts can signal weakened immunity, which may require further evaluation for conditions like HIV, autoimmune diseases, or chemotherapy side effects. High counts may point to chronic infections, inflammatory diseases, or reactive immune responses.

Short name

Lymphocyte Count

Frequently asked questions

How often should I get this test?
The frequency depends on your health condition and why the test was ordered. If you have an ongoing medical issue, your provider may recommend regular monitoring. For routine check-ups, it’s usually not a standard test unless symptoms or risk factors suggest it.
What can affect my lymphocyte count?
Several factors can influence lymphocyte counts, including infections (like colds or flu), stress, certain medications (e.g., steroids), chronic illnesses (like diabetes or heart disease), and even sleep deprivation. Smoking or alcohol use may also temporarily affect immune cell counts.
Can I prepare for this test differently based on my condition?
If you’re on medications that might affect your immune system (e.g., chemotherapy, immunosuppressants), let your provider know before the test. For general blood draws, avoid strenuous activity or heavy meals 1–2 hours before the test to ensure accurate results, though this isn’t always necessary for lymphocyte counts alone.
  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