Lymphocyte count in whole blood
This test measures the number of lymphocytes, a type of white blood cell important for fighting infections and maintaining immunity. It helps assess immune function and identify conditions affecting lymphocyte levels.
["Lymphocytes help protect your body from infections and diseases by detecting and destroying harmful invaders."]
Key facts at a glance
- LOINC
- 30120-0
- Short code
- Lymphs IgD # WBC
- Synonyms
- Lymphs IgD # WBC
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85004
- SNOMED
- 900000000000003002
- 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 Might Be Ordered
Your healthcare provider may order this test to evaluate your immune system, diagnose conditions like infections, autoimmune diseases, or blood disorders, or monitor treatment responses for conditions such as leukemia or lymphoma.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm or hand to draw blood. If you’re nervous, let your provider know—they can offer ways to make it more comfortable.
What the Test Results Mean
Results show the absolute lymphocyte count (typically in cells per microliter). Low levels may suggest immune suppression, high levels could indicate chronic infections or certain cancers. Always discuss results with your provider.
Common Conditions Affecting Lymphocyte Counts
Changes in lymphocyte counts can signal conditions like HIV/AIDS, lymphoma, or autoimmune diseases (e.g., lupus). They may also appear in response to infections, stress, or certain medications.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: Lymphocyte counts are critical for diagnosing and managing immune-related disorders. Low counts may require immune support or treatment adjustments, while elevated counts could prompt further investigation into chronic infections or malignancies.
Short name
Lymphocyte Count (WBC Differential)
Frequently asked questions
What causes a low lymphocyte count?
What causes a high lymphocyte count?
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