There can be a relationship between severe hypothyroidism and high cholesterol. However, if you've been on synthetic thyroid medications for over a year, then I would assume that you have your thyroid hormone replaced which means that your cholesterol levels and the thyroid issues would not be related. Since you are still exhausted and sleeping over 13 hours per day, then I would suggest that you schedule an appointment with whoever you are following for your hypothyroidism so you can have your TSH checked. the TSH, or thyroid stimulating hormone, is the most sensitive test to determine how your thyroid levels are. If your TSH level is normal, then your fatigue and other symptoms including your cholesterol issues are not due to the hypothyroidism. Because of your multiple issues, I would suggest that you schedule an appointment with an endocrinologist
who is a specialist both in lipid medicine and thyroid gland conditions. Your endocrinologist will likely take a detailed family history to find out if there is a genetic component to why your cholesterol levels are high. In addition, he or she can look at the levels and determine whether or not you need your pravastatin dosing changed. In the end, all that matters is that you get to cholesterol levels in the normal range so that you can reduce your risk for cardiovascular disease.