My father has essential thrombocytosis and high cholesterol. his hs, crp (c reactive protein) was a high 4.5. he now takes a statin. is that serious?

Not a long: as his c-crp remains low total cholesteraol is normal , HDL is 35-45 and LDL is less than 150. I advise 1 baby aspirin-81mg daily along with cross training 3-4 times weekly and depending on current weight 5-15 lb. weight loss over 3 months.

Ess thrombocytosis: It is good that high cholestrol is being treated appropriately. Generally, patients are able to lead a normal life but risk stratification includes other factors as well like - age, mutations ( another test), history of blood clots in the past, general health etc.