Elevated ldl(164) ldl:hdl-3.6, tot chol:234 , thyroid under control with synthyroid. can i try to control with diet and exercise instead of medication?

ITS POSSIBLE: Whether you should be on meds or not depends on your other risk factors for heart disease.

Yes, If Follow LDL-P: In addition to these labs, you should have LDL particle number (ldl-p) checked. Ldl cholesterol (ldl-c) is commonly used to "estimate" the number of LDL particles. However, because the amount of cholesterol carried inside LDL is so variable, ldl-c often underestimates ldl-p. When ldl-c and ldl-p differ cardiovascular risk tracks with ldl-p, not ldl-c. Regardless of diet or medication follow ldl-p.