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Lymphocyte Count, Whole Blood — Manual Method

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

A manual blood differential that measures the number or proportion of lymphocytes in a whole-blood sample.

Quick summary

["This test helps evaluate immune-cell levels and can identify changes suggesting infection or other blood disorders."]

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

Key facts at a glance

LOINC
33833-5
Short code
Ib Lymphs NFr Bld Manual
Synonyms
Ib Lymphs NFr Bld Manual
Category
liver
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

What is this test?

This test measures lymphocytes, a type of white blood cell involved in immune defense. The result may report the lymphocyte count or the percentage of white blood cells that are lymphocytes.

Why might I need this test?

It may be ordered as part of a routine complete blood count or blood differential, during evaluation of an infection, or when monitoring immune or blood-related conditions. It can also help assess the effects of certain medicines.

How is the test performed?

A blood sample is collected and a blood smear is examined, usually by a laboratory professional using a microscope. If the result is unexpected or the cells appear unusual, additional blood-flow or genetic studies may be needed.

How do I prepare for the test?

No special preparation is usually required for a routine blood draw. Follow any instructions from your healthcare professional and tell the laboratory about recent infections, steroid use, or other medicines that may affect blood-cell results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A lower lymphocyte count may occur with certain viral infections, some medicines, immune disorders, or conditions affecting blood-cell production. A higher count may occur with infections, inflammation, or some immune and lymphoproliferative disorders. Results should be interpreted with symptoms, medical history, and the other blood-count results.

Short name

Manual blood lymphocyte count

Frequently asked questions

Is this the same as a complete blood count?
It is often included as part of a complete blood count and its differential. A complete blood count also measures other blood cells, such as red cells, white cells, and platelets.
Does a manual lymphocyte count require a separate blood draw?
Usually not. The manual differential is generally performed using the same whole-blood sample collected for other blood-count tests.
What if my result is outside the laboratory's reference range?
An abnormal result does not by itself identify a specific condition. Your clinician can review it with the rest of your blood count, symptoms, medications, and medical history.
  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