Lymphocyte Differential Count (Manual Blood Film Examination)
This test evaluates the types and proportions of white blood cells called lymphocytes in your blood, using a microscopic examination of a blood smear. It helps identify abnormalities in immune cell distribution.
["This test assesses immune cell balance and may help diagnose conditions affecting white blood cells."]
Key facts at a glance
- LOINC
- 98022-7
- Short code
- Lymph Abn Fld Ql Manual
- Synonyms
- Lymph Abn Fld Ql 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
- 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
Your healthcare provider may order this test if you have symptoms like frequent infections, unexplained fatigue, or signs of immune system issues. It can also be used to monitor conditions like leukemia, lymphoma, or immune deficiencies.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm to draw blood, similar to other blood tests. If you’re on blood thinners, let your provider know to avoid unnecessary bleeding.
What Happens During the Test
A healthcare professional will take a small blood sample and spread it thinly on a glass slide. A trained technician will then examine the slide under a microscope to count and classify different lymphocyte types.
What the Results Mean
Results show the percentage and absolute count of different lymphocyte subtypes (e.g., B cells, T cells, natural killer cells). Abnormal counts may indicate immune disorders, infections, or other blood-related conditions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Manual Lymphocyte Count
Frequently asked questions
A lymphocyte differential helps diagnose immune-related diseases, such as chronic infections, autoimmune disorders, or cancers like lymphoma. It may also guide treatment decisions for conditions affecting white blood cell function.
The results may take several days to process, depending on lab workload. Follow-up with your provider to discuss findings and next steps.
This test does not require fasting or dietary restrictions, but inform your provider about any medications or supplements you’re taking that could affect blood 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