Hi @winmil99 HCT (hematocrit) measures how much of your blood consists of red blood cells. Platelets and white blood cells are the other components in your blood.
All of these components are generally proportionally balanced within specific ranges in a healthy person.
When one or more element is either too high or too low, it can be an indication of infection or condition causing the over or under production of blood cells, either red, white or platelets. HCT doesn’t necessarily impact platelets directly but overall, if platelets and red blood counts are out of the norm, it may indicate an underlying health issue.

Here’s a great article about HCT from verywellhealth.com
https://www.verywellhealth.com/hematocrit-level-test-1942505
Are your hemoglobin and HCT elevated along with your platelets?