Lymphocyte Count (Manual Differential Blood Count)
This test measures the types and proportions of white blood cells called lymphocytes in your blood, which helps assess immune function and identify potential infections or disorders.
["Understanding your lymphocyte breakdown can help doctors diagnose immune-related conditions."]
Key facts at a glance
- LOINC
- 13941-0
- Short code
- Lymphocytes NFr Fld Manual
- Synonyms
- Lymphocytes NFr 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
- 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
Doctors may order this test to evaluate your immune system, check for infections (like mononucleosis or lymphoma), monitor conditions such as leukemia, or assess immune deficiencies. It’s also used in cancer treatment follow-ups to monitor white blood cell responses.
What to Expect Before the Test
No special preparation is needed. You’ll provide a simple blood sample, usually drawn from your arm. If you’re on blood thinners, let your doctor know before the test.
What the Results Mean
Results show the percentage of lymphocytes among all white blood cells. A normal range varies by lab, but low or high counts may signal immune issues, infections, or other health concerns. Your doctor will interpret results in the context of your overall health.
Common Conditions Affecting Results
Lymphocyte counts can be low in immune disorders (e.g., HIV/AIDS), chronic infections, or certain cancers. They may be elevated in acute infections, autoimmune diseases, or overactive immune responses.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal lymphocyte counts can signal underlying health issues, such as immune system dysfunction, infections, or cancers like lymphoma. This test is a key part of diagnosing and managing these conditions, often used alongside other blood tests or imaging.
Short name
Lymphocyte Differential
Frequently asked questions
What does a low lymphocyte count mean?
How often should I get this test?
Can diet or lifestyle affect lymphocyte counts?
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