Lymphocyte count (qualitative blood smear review)
This test evaluates the number of lymphocytes, a type of white blood cell, by examining a microscopic image of your blood under a microscope. It helps assess immune function and identify potential infections or immune disorders.
["Lymphocytes are key to fighting infections and maintaining immune health—this test helps track their levels for diagnosis or monitoring."]
Key facts at a glance
- LOINC
- 71673-8
- Short code
- Lymphocytes NFr.DF Bld Manual
- Synonyms
- Lymphocytes NFr.DF 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 This Test Is Done
Doctors may order this test to diagnose or monitor conditions affecting your immune system, such as infections (e.g., viral or bacterial), immune deficiencies, or certain blood disorders. It can also be part of routine check-ups or follow-up care for chronic illnesses like cancer or autoimmune diseases.
How the Test Works
A small sample of your blood is drawn and examined under a microscope by a trained technician. The technician counts and identifies different types of white blood cells, including lymphocytes, to determine their relative proportion.
What to Expect Before the Test
No special preparation is needed. You may have a slight bruise or soreness at the needle insertion site, but this usually fades quickly. If you’re on blood-thinning medication, let your doctor know before the test.
What to Expect During the Test
You’ll lie down comfortably while a healthcare provider inserts a needle into a vein (usually in your arm). The blood sample is collected into a small tube, and the needle is removed. The process takes just a few minutes.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Lymphocyte count (manual)
Frequently asked questions
What does a low lymphocyte count mean?
What does a high lymphocyte count mean?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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