Skip to content

Plasma/Serum Platelet Count (with Differential Analysis)

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

This blood test measures the number of platelets and the proportions of different types of white blood cells (differential count) to assess blood clotting function and infection risk.

Quick summary

["Platelets help prevent bleeding, and white blood cells fight infections."]

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

Key facts at a glance

LOINC
112022-9
Short code
Stent placement site PD Endscpy
Synonyms
Stent placement site PD Endscpy
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
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 to check for bleeding disorders, infections, or immune system issues. It’s also used before surgeries or procedures that could affect blood clotting.

What to Expect Before the Test

No special preparation is needed, but avoid aspirin or certain blood thinners for 5–7 days before testing if your doctor advises it. Fast for 8–12 hours if a fasting specimen is required (though this test is not fasting-specific).

What the Results Mean

A platelet count measures total platelets, while the differential shows the percentage of each white blood cell type (neutrophils, lymphocytes, monocytes, eosinophils, basophils). Low platelet counts may indicate bleeding risks, while abnormal white blood cell counts can signal infections or inflammation.

Common Conditions Monitored

This test helps diagnose or monitor conditions like thrombocytopenia (low platelets), leukemia (cancer of blood cells), or autoimmune diseases that affect white blood cells.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Platelets are essential for clotting, and their count helps identify bleeding disorders. The differential count reveals whether infections or immune problems are affecting your blood. Abnormal results may prompt further testing or treatment to address underlying causes.

Short name

Platelet Count with Differential

Frequently asked questions

How long does it take to get results?
Results are typically available within 1–2 business days, depending on lab processing times. Follow-up with your doctor if you have questions about your specific results.
Can I eat or drink before this test?
No fasting is required for this test, but avoid heavy meals or alcohol 24 hours before to ensure accurate results. If your doctor specifies fasting for another reason, follow their instructions.
What if my platelet count is low?
A low platelet count may signal bleeding risks or conditions like vitamin deficiencies (e.g., B12 or folate) or medications affecting platelet production. Your doctor will discuss next steps, which may include blood transfusions, medication adjustments, or further testing.
  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