What would be considered a high platelet count

Hello Anon

Thank you for writing!

Accord to Johns Hopkins:
"A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Having more than 450,000 platelets is a condition called thrombocytosis; having less than 150,000 is known as thrombocytopenia."

High platelets can be due to many conditions such as anemia, infections, cancer and others. You need to discuss with your doctor your condition and treatment.
Best,
Susan