joyce,   Thanks for your question.   First of all, if your hypothyroidism is active, or inadequately treated, this could cause a rise in your cholesterol level.  Most of the medication used for the treatment of your hypothyroidism and your asthma should not affect the level of cholesterol.   You should discuss this with your doctor.  If your thyroid status is under control, then it is time to address the cholesterol level.  Certainly diet, low in cholesterol and saturated fats, and and exercise program should be initiated.  If this is unsuccessful, then medication might have to be a consideration.  Of course, your other lipid levels need to be checked, such as LDL, Triglycerides, and HDL.   Hope this was helpful.  Be sure to review this website for tips on ways to get your cholesterol under control without medication.   Martin Cane, M.D.