Biomarker · Blood count

Platelet count

Platelets help blood clot. What a platelet count measures, what low or high counts can mean, and how the test fits into a complete blood count.

Written by LON6EVITY Editorial Team · Last updated

About LON6EVITY. A longevity and prevention platform that keeps your biomarkers, screenings and health history in one place, shows trends over time and prepares doctor-ready reports. How it works

What platelets do

Platelets are small cell fragments that help form clots to stop bleeding.

Low and high counts

MedlinePlus explains that a low platelet count (thrombocytopenia) can increase the risk of bleeding and can be caused by some medicines, infections, liver disease or bone marrow problems. A high count (thrombocytosis) may be a reaction to infection, inflammation or iron deficiency, or less often a bone marrow disorder.

How it is tested

The platelet count is part of a standard complete blood count. Further tests may be ordered depending on the result.

Reference ranges

Reference ranges differ between laboratories, units and methods, and depend on age, sex and your overall clinical picture. A single result is not a diagnosis — interpret it with a qualified clinician.

Factors that can affect the result

  • Medicines
  • Infection and inflammation
  • Iron deficiency
  • Liver disease
  • Alcohol

Questions people commonly ask

Can iron deficiency affect platelets?
Yes. Iron deficiency is one of the recognised causes of a raised platelet count.

Related biomarkers

Related tests

Understand your biomarkers in context

What does this mean for your own health data? Log your results, follow trends over time and bring an organised summary to your next doctor's appointment.

Build your longevity profileSee membership

Sources

  1. Platelet Tests. MedlinePlus, U.S. National Library of Medicine.
  2. Complete Blood Count (CBC). MedlinePlus, U.S. National Library of Medicine.