Platelet Count
Cell fragments that help blood clot
20 of 22 providers
Complete Blood Count (CBC)
150-400 thousand/μL
What is Platelet Count?
Platelet Count measures the number of platelets (thrombocytes) in your blood. Platelets are small cell fragments produced in bone marrow that play a critical role in blood clotting and wound healing. Normal platelet count is 150,000-400,000 per microliter (μL). Platelets live only 7-10 days, so bone marrow must constantly produce new platelets.
When blood vessels are damaged, platelets rapidly adhere to the injury site, activate, and aggregate to form a platelet plug, initiating the clotting cascade. They also release growth factors that promote tissue repair. Low platelet count (thrombocytopenia) increases bleeding risk, while high count (thrombocytosis) can increase clotting risk, though less predictably than low counts increase bleeding.
Platelet count is one of the most variable blood parameters, fluctuating with inflammation, stress, and certain conditions. Mild elevations (400,000-600,000) are often reactive (secondary thrombocytosis) to infection, inflammation, or iron deficiency and rarely cause problems. Very high counts (>1,000,000) or very low counts (<50,000) require urgent evaluation. Platelet function is as important as count—some people with normal counts have dysfunctional platelets causing bleeding.
Why Platelet Count Is Critical for Clotting and Safety
- Bleeding risk assessment:Platelet <50,000 increases bleeding risk. <20,000 causes spontaneous bleeding requiring urgent treatment
- Surgical safety:Platelet >50,000 generally safe for surgery. <50,000 may require platelet transfusion before procedures
- Medication monitoring:Chemotherapy, immunosuppressants, and some antibiotics can cause life-threatening thrombocytopenia
- Thrombosis risk:Very high platelets (>1,000,000 in myeloproliferative disorders) paradoxically increase both bleeding and clotting
- ITP diagnosis:Isolated low platelets with normal WBC/RBC suggests immune thrombocytopenia requiring specific treatment
- Early cancer detection:Persistent unexplained thrombocytosis may indicate occult malignancy
Optimal vs Standard Ranges
Optimal180,000-320,000 /μL▼
- Ideal range for hemostasis without increased thrombosis risk
- Provides adequate clotting capacity with minimal risk of either bleeding or thrombotic complications
Borderline130,000-180,000 or 320,000-450,000 /μL▼
- Low-normal may indicate mild ITP, bone marrow suppression, or viral infection
- High-normal often reactive to inflammation, iron deficiency, or recent bleeding
- Monitor with repeat CBC in 4-8 weeks
Thrombocytopenia<150,000 /μL▼
- Low platelets
- Mild (100,000-150,000):Usually asymptomatic, monitor closely
- Moderate (50,000-100,000):Increased bleeding with trauma/surgery, avoid contact sports
- Severe (<50,000):High bleeding risk, may require treatment
- Critical (<20,000):Spontaneous bleeding risk, urgent hospitalization and treatment needed
Thrombocytosis>450,000 /μL▼
- Elevated platelets
- Reactive (450,000-700,000):Usually from infection, inflammation, iron deficiency, bleeding, or splenectomy
- Benign, treat underlying cause
- Primary (>600,000):May indicate myeloproliferative disorder (essential thrombocythemia, polycythemia vera, myelofibrosis)
- Requires JAK2 mutation testing and hematology referral
- Extreme (>1,000,000):High risk bleeding/clotting, urgent treatment
Scientific Evidence
Bleeding Risk and Platelet Count
Bleeding risk increases significantly below 50,000 platelets, especially with trauma or surgery. Spontaneous bleeding is rare above 20,000 but increases dramatically below this threshold. Prophylactic platelet transfusion for counts <10,000 reduces serious bleeding events by 50% in hematology patients.
ITP Management Guidelines
In immune thrombocytopenia, treatment is indicated for platelets <30,000 with bleeding or <20,000 even without bleeding. First-line treatment is corticosteroids (prednisone 1 mg/kg) with 70-80% response rate. IVIG provides rapid platelet increase for emergencies. TPO receptor agonists are effective second-line therapy.
Essential Thrombocythemia and Thrombosis
In essential thrombocythemia, thrombosis risk is increased 2-3 fold. Low-dose aspirin (81 mg daily) reduces thrombotic events by 60%. Cytoreductive therapy (hydroxyurea) for high-risk patients (age >60, prior thrombosis) reduces events by additional 50%. Target platelet count <400,000.
Heparin-Induced Thrombocytopenia
HIT occurs in 1-5% of patients receiving heparin, typically 5-10 days after starting therapy. Despite low platelets (usually 50,000-150,000), HIT causes paradoxical thrombosis in 30-50% of cases. Immediate heparin cessation and initiation of direct thrombin inhibitor is critical. Delay increases limb loss and death risk.
Source:Warkentin TE, et al. Heparin-induced thrombocytopenia in patients treated with low-molecular-weight heparin or unfractionated heparin. N Engl J Med. 1995;332(20):1330-1335.
Reactive Thrombocytosis Prognosis
Reactive thrombocytosis (platelets 450,000-700,000 from infection, inflammation, or iron deficiency) is generally benign and does not increase thrombosis risk. Treatment of underlying cause normalizes platelets. Routine antiplatelet therapy is not indicated. However, persistent unexplained thrombocytosis warrants investigation for occult malignancy or myeloproliferative disorder.
Source:Schafer AI. Thrombocytosis. N Engl J Med. 2004;350(12):1211-1219.
Which Providers Test Platelet Count?
Full Provider Comparison
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | ✓ | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | ✓ | $349 | 65 |
 Labcorp OnDemand | ✓ | $398 | 30+ |
| ✓ | $486 | 40+ | |
| ✓ | $444 | 288 | |
| ✓ | $349 | 100+ | |
| ✓ | $761 | 54 | |
 Function Health | ✓ | $365 | 160+ |
| ✓ | $250 | 65 | |
| ✓ | $495 | 70+ | |
| ✓ | $895 | 100+ | |
| ✓ | $1950 | 150+ | |
| ✓ | $375 | 80+ | |
| — | $Varies | 75+ | |
| ✓ | $190 | 100+ | |
| ✓ | $99 | 50 | |
| — | $124 | 60 | |
| ✓ | $199 | 50 | |
| ✓ | $499 | 120+ | |
| ✓ | $4188 | 70-80+ | |
| ✓ | $375 | 85 | |
| ✓ | $700 | 128 |
Frequently Asked Questions
What is Platelet Count?
Cell fragments that help blood clot
What is the optimal range for Platelet Count?
The standard reference range for Platelet Count is 150-400 thousand/μL. Optimal ranges may differ based on individual health goals and expert recommendations.
Which blood test providers include Platelet Count?
20 out of 22 blood testing providers include Platelet Count in their panels. This biomarker is widely available across major providers.
What category does Platelet Count fall under?
Platelet Count is categorized under Complete Blood Count (CBC). This category includes biomarkers that help assess related aspects of health and wellness.
Medical Disclaimer
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
Last reviewed:2026-02-20