Platelet Count
- Sample Type
- Whole Blood
- Fasting
- No
- Unit
- 10^3/µL
Function
Platelets, or thrombocytes, are small cell fragments in the blood that are essential for normal blood clotting. When a blood vessel is injured, platelets migrate to the site, adhere to the damaged surface, and clump together to form a 'platelet plug.' They also release chemicals that activate the clotting cascade. The platelet count measures the number of these fragments per microliter of blood, serving as a primary indicator of the body's ability to maintain hemostasis.
Why it is Ordered
A platelet count is part of a standard Complete Blood Count (CBC). It is specifically ordered for:
- Surgical Clearance: To ensure a patient can clot properly during and after an operation.
- Unexplained Bruising/Bleeding: Investigating petechiae (small red dots), frequent nosebleeds, or heavy menstrual cycles.
- Monitoring Bone Marrow: To check the impact of chemotherapy or radiation on blood cell production.
- Monitoring Chronic Conditions: Managing patients with known liver disease or autoimmune disorders.
Associated Conditions
Abnormal platelet counts are linked to various health states. Thrombocytopenia (low count) can be caused by immune destruction (ITP), sequestration in an enlarged spleen, or bone marrow failure. Thrombocytosis (high count) may be 'reactive' (due to inflammation, iron deficiency, or infection) or 'essential' (a primary bone marrow disorder like Essential Thrombocythemia). Extremely high counts increase the risk of inappropriate blood clots (thrombosis), while extremely low counts (<20,000) carry a high risk of spontaneous internal bleeding.
Check Your Result
Check Your Result
Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
Platelet counts are prone to 'Pseudothrombocytopenia,' a laboratory artifact where platelets clump together in the EDTA collection tube, causing the machine to miscount them as single large cells. This results in a falsely low reading. Additionally, intense physical exercise or high stress shortly before the blood draw can transiently increase the count. If a result is unexpectedly low, a 'peripheral blood smear' should be performed to manually verify the count.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Platelet Count:
Official Sources
- ASH Clinical Practice Guidelines on Immune ...hematology.org
Research & Guidelines
- PubMed: Platelet Count Clinical GuidelinesNCBI / PubMed
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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