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Lymphocyte Count with Differential Screening (Peripheral Blood)

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

This test measures the types and numbers of white blood cells called lymphocytes in your blood, which helps assess immune function and detect abnormalities like infections, inflammation, or blood disorders.

Quick summary

["Understanding your lymphocyte counts can help identify immune or blood-related concerns."]

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

Key facts at a glance

LOINC
54229-0
Short code
Lymphoma - T-cell screen Pnl Spec FC
Synonyms
Lymphoma - T-cell screen Pnl Spec FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
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 doctor may order this test if you have symptoms like frequent infections, unexplained fatigue, swollen lymph nodes, or if they suspect conditions such as leukemia, lymphoma, or immune deficiencies. It can also be part of routine blood work or monitoring for chronic illnesses.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw a small amount of blood. It usually takes about 15 minutes, and you can resume normal activities afterward.

What the Test Results Mean

The test provides a breakdown of your total lymphocyte count and the proportions of different lymphocyte subtypes (e.g., B cells, T cells, natural killer cells). Abnormal results may indicate immune system issues or other health concerns that need further evaluation.

Common Conditions Monitored

This test helps diagnose or monitor conditions like chronic infections, autoimmune diseases, or blood cancers. It may also be used to track response to treatments for these conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lymphocyte Screen

Frequently asked questions

How long will I need to wait for my results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your healthcare provider will discuss the findings with you during your follow-up visit.
Can I eat or drink before this test?
No special diet or fasting is required for this test. You can eat and drink normally, as it’s a simple blood draw.
What if my lymphocyte counts are abnormal?
If your results are outside expected ranges, your doctor may recommend additional tests or treatments to address potential underlying conditions, such as infections, immune disorders, or blood cancers.
  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