Skip to content

Lymphocyte Count (Manual Blood Cell Differential)

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 are crucial for immune defense; abnormal counts may signal infection, inflammation, or immune disorders."]

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

Key facts at a glance

LOINC
29262-3
Short code
Lymph Abn # Bld Manual
Synonyms
Lymph Abn # Bld Manual
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to check for infections, monitor immune function, diagnose conditions like lymphoma or leukemia, or evaluate symptoms such as frequent infections, fatigue, or unexplained weight loss.

What to Expect Before the Test

No special preparation is needed. You may have a simple blood draw, often done in a clinic or lab. The process is quick and usually painless.

What the Results Mean

Results show the absolute lymphocyte count (number per microliter of blood). Low counts may indicate immune suppression, high counts could suggest chronic infections or certain cancers. Your provider will interpret results in the context of your overall health.

Common Conditions Affecting Lymphocyte Counts

Low lymphocyte counts can occur with HIV/AIDS, chemotherapy, or autoimmune diseases like lupus. High counts may be seen in chronic infections (e.g., tuberculosis), certain cancers, or after vaccination.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Abnormal lymphocyte counts often prompt further investigation, such as additional blood tests, imaging, or biopsies, to identify underlying causes like infections, cancers, or immune disorders.

Short name

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 weaken the immune system, such as malnutrition or chronic stress.
What causes a high lymphocyte count?
High lymphocyte counts may be due to chronic infections, certain cancers (e.g., leukemia), inflammatory conditions, or reactions to vaccines or medications. Your provider will assess symptoms and other test results to determine the cause.
Can lifestyle changes affect lymphocyte counts?
Yes, lifestyle factors like diet, sleep, and stress can influence immune function. Maintaining a balanced diet, managing stress, and staying hydrated may support healthy lymphocyte levels, but this test alone cannot diagnose underlying issues.
  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