Cell fragments that help blood clot
20 of 22 providers
Complete Blood Count (CBC)
150-400 thousand/μL
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.
| Range Type | Level | Significance |
|---|---|---|
| Optimal | 180,000-320,000 /μL | Ideal range for hemostasis without increased thrombosis risk. Provides adequate clotting capacity with minimal risk of either bleeding or thrombotic complications. |
| Borderline | 130,000-180,000 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. |
Corticosteroids:Prednisone 1 mg/kg daily for 2-4 weeks. Raises platelets in 70-80% within days to weeks. Taper slowly
IVIG (Intravenous Immunoglobulin):1 g/kg for acute severe ITP (<20,000 with bleeding). Rapid platelet increase within 24-48 hours
Romiplostim or Eltrombopag:TPO receptor agonists stimulate platelet production. For chronic ITP unresponsive to steroids
Rituximab:Anti-CD20 antibody depletes B-cells. Effective in 60% of ITP cases
Splenectomy:If refractory to medical therapy. Cures ITP in 60-70% but increases infection risk
Avoid:Aspirin, NSAIDs, other antiplatelet/anticoagulant drugs if platelets <50,000
Reactive thrombocytosis:Treat underlying cause (infection, inflammation, iron deficiency). Platelets normalize when cause resolves. No specific treatment needed
Essential thrombocythemia:Low-dose aspirin 81 mg daily reduces thrombosis risk. Hydroxyurea if high risk (age >60, platelets >1,500,000, prior thrombosis)
Extreme thrombocytosis (>1,000,000):Urgent cytoreduction with hydroxyurea or anagrelide. Platelet pheresis if acute thrombosis
Avoid unnecessary antiplatelet:Not all thrombocytosis requires aspirin. Risk vs benefit assessment needed
Iron repletion:If iron deficiency causing reactive thrombocytosis, platelets normalize with iron supplementation
High-risk medications:Heparin (HIT—heparin-induced thrombocytopenia), quinine, sulfa drugs, vancomycin, linezolid, chemotherapy
Monitor closely:Check platelet count every 2-3 days when starting heparin. Weekly with chemotherapy
Discontinue offending drug:If drug-induced thrombocytopenia suspected, stop medication immediately. Platelets recover within 5-10 days in most cases
HIT management:Stop all heparin immediately. Start direct thrombin inhibitor (argatroban, bivalirudin). HIT causes paradoxical thrombosis despite low platelets
Chemotherapy support:Platelet transfusion if <10,000 or bleeding. Consider dose reduction or growth factors
Prophylactic transfusion:If platelets <10,000 to prevent spontaneous bleeding. Each unit raises platelets by ~30,000-50,000
Pre-procedure transfusion:Transfuse if <50,000 before surgery or invasive procedures. Lower thresholds for low-risk procedures
Active bleeding:Transfuse to maintain platelets >50,000 during active hemorrhage
Platelet refractoriness:Some patients don't respond to transfusions due to antibodies. May need HLA-matched platelets
ITP exception:Avoid transfusion in ITP unless life-threatening bleeding—transfused platelets are rapidly destroyed
If low platelets (<50,000):Avoid contact sports, alcohol (impairs platelet function), NSAIDs/aspirin. Use soft toothbrush. Report any bleeding
If high platelets (>450,000):Stay hydrated (dehydration increases thrombosis risk), consider aspirin if essential thrombocythemia
Nutrition:Ensure adequate B12, folate for platelet production. Omega-3 may reduce platelet reactivity (discuss with doctor if on anticoagulants)
Bleeding precautions:If platelets <20,000, avoid IM injections, rectal temperatures, constipation (straining). Pad sharp corners at home
Regular monitoring:Check platelets weekly if <50,000, monthly if 50,000-100,000, every 3 months if >450,000
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.
Source:Slichter SJ, et al. Dose of prophylactic platelet transfusions and prevention of hemorrhage. N Engl J Med. 2010;362(7):600-613.
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.
Source:Neunert C, et al. American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019;3(23):3829-3866.
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.
Source:Barbui T, et al. Philadelphia chromosome-negative classical myeloproliferative neoplasms:revised management recommendations. Leukemia. 2018;32(5):1057-1069.
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 (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.
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | ✓ | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | ✓ | $349 | 65 |
 Labcorp OnDemand | ✓ | $398 | 30+ |
| ✓ | $486 | 40+ | |
| ✓ | $468 | 83 | |
| ✓ | $349 | 100+ | |
 InsideTracker | ✓ | $680 | 54 |
 Function Health | ✓ | $365 | 100+ |
| ✓ | $250 | 65 | |
| ✓ | $495 | 70+ | |
| ✓ | $895 | 100+ | |
| ✓ | $1950 | 150+ | |
| — | $399 | 100+ | |
| — | $Varies | 75+ | |
| ✓ | $190 | 100+ | |
| ✓ | $99 | 50 | |
| — | $125 | 60 | |
| ✓ | $199 | 50 | |
| ✓ | $499 | 120+ | |
| ✓ | $4188 | 80+ | |
| ✓ | $375 | 85 | |
| ✓ | $700 | 129 |
20 providers include this biomarker in their panels
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
