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Platelet Count (Peripheral Blood)

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

This test measures the number of platelets in your blood, which are tiny cells that help prevent bleeding by clotting blood vessels. Platelets are crucial for normal healing after cuts or injuries.

Quick summary

["Platelets help stop bleeding and promote healing—low or high levels may signal health concerns."]

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

Key facts at a glance

LOINC
51873-8
Short code
Platelet conc Gvn BPU
Synonyms
Platelet conc Gvn BPU
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
150
Ref high
400
Critical range
50 N/A – 1000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85049
SNOMED
900000000000003003
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 Is This Test Done?

Doctors may order a platelet count to check for bleeding disorders, infections, or conditions like leukemia. It’s often part of a routine blood test or when you experience unusual bruising, bleeding, or fatigue.

What to Expect Before the Test

You’ll likely have a simple finger prick or vein draw. No special prep is needed, but inform your provider about medications (like blood thinners) or recent illnesses that might affect results.

How the Test Works

Blood is drawn and analyzed to count platelets. The test is quick and painless, with results available within hours or the next day.

Possible Results & What They Mean

A normal platelet count is usually between 150,000 and 450,000 per microliter. Very low counts (thrombocytopenia) may increase bleeding risk, while very high counts (thrombocytosis) could signal inflammation or other issues.

Reference range

Adult: 150-400 x 10^9/LN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Platelet counts can be affected by infections, medications (like chemotherapy), autoimmune diseases, or severe stress. Chronic conditions like kidney disease or liver problems may also influence levels.

Short name

Platelet Count

Frequently asked questions

What causes low platelet counts?
Low platelet counts can result from conditions like immune disorders, certain medications, or bone marrow problems. Symptoms may include easy bruising or bleeding, but some people have no symptoms at all.
What causes high platelet counts?
High platelet counts may occur due to infections, inflammation, or cancer. They can sometimes cause blood clots or other complications, though this isn’t always the case.
Can diet affect platelet counts?
Dietary factors like vitamin K, vitamin C, or certain supplements may influence platelet function, but they don’t typically change the platelet count itself. Always discuss dietary changes with your provider.
  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