Platelet Count: What It Is and What Your Results Mean

Name: Platelet Count: What It Is and What Your Results Mean
Creator: Ernestas K.

Bottom line: Platelets help your blood clot. Normal is 150-400 K/uL. Low platelets increase bleeding risk, high platelets increase clotting risk.

What Is Platelet Count?

Platelets (thrombocytes) are tiny blood cells that help your body form clots to stop bleeding. When a blood vessel is damaged, platelets rush to the site, stick together, and form a plug that seals the wound.

A platelet count is part of a complete blood count (CBC). Low platelets (thrombocytopenia) increase bleeding risk, while high platelets (thrombocytosis) can increase clotting risk. Both conditions can range from mild and incidental to serious and requiring treatment.

Platelet counts can fluctuate temporarily due to infections, inflammation, medications, or recent surgery. Persistent abnormalities should be investigated.

Platelet Count Reference Ranges

Classification	Range (K/µL)
Severely Low (Severe Thrombocytopenia)	Below 50
Low (Thrombocytopenia)	50 - 99
Mildly Low	100 - 149
Normal	150 - 400
Mildly Elevated	401 - 600
High (Thrombocytosis)	601+
Very High	1001+

What Affects Your Platelet Count Levels?

Infections and inflammatory conditions
Autoimmune disorders
Bone marrow function
Medications including blood thinners and chemotherapy
Liver disease and alcohol consumption
Vitamin B12 and folate deficiency

When to Get Tested

Platelets are routinely measured as part of a CBC during annual physicals. Additional testing if you have unusual bleeding or bruising, a known blood disorder, or are on medications that affect platelet count.

Look Up Your Platelet Count Result

Select your value below to see a detailed breakdown of what it means:

Severely Low (Severe Thrombocytopenia)

Platelet Count 10 K/µL Platelet Count 20 K/µL Platelet Count 30 K/µL Platelet Count 40 K/µL

Low (Thrombocytopenia)

Platelet Count 50 K/µL Platelet Count 60 K/µL Platelet Count 70 K/µL Platelet Count 80 K/µL Platelet Count 90 K/µL

Mildly Low

Platelet Count 100 K/µL Platelet Count 110 K/µL Platelet Count 120 K/µL Platelet Count 130 K/µL Platelet Count 140 K/µL

Normal

Platelet Count 150 K/µL Platelet Count 175 K/µL Platelet Count 200 K/µL Platelet Count 225 K/µL Platelet Count 250 K/µL Platelet Count 275 K/µL Platelet Count 300 K/µL Platelet Count 325 K/µL Platelet Count 350 K/µL Platelet Count 375 K/µL Platelet Count 400 K/µL

Mildly Elevated

Platelet Count 425 K/µL Platelet Count 450 K/µL Platelet Count 500 K/µL Platelet Count 550 K/µL Platelet Count 600 K/µL

High (Thrombocytosis)

Platelet Count 650 K/µL Platelet Count 700 K/µL Platelet Count 750 K/µL Platelet Count 800 K/µL Platelet Count 900 K/µL Platelet Count 1000 K/µL

Read the Full Blood Test Guide

Frequently Asked Questions

What is a normal platelet count?

150,000 to 400,000 per microliter (150-400 K/uL) is normal. Below 150 K/uL is thrombocytopenia. Above 400 K/uL is thrombocytosis.

Should I worry about slightly low platelets?

Mildly low platelets (100-149 K/uL) are often incidental and not clinically significant. They should be monitored with a repeat test in a few months. Levels below 100 K/uL warrant further investigation.

What causes high platelets?

Reactive thrombocytosis (from infection, inflammation, iron deficiency, or surgery) is the most common cause and usually resolves. Primary thrombocytosis from a bone marrow disorder is less common but requires monitoring.

Ernestas K.

Clinical Research Writer