Hi there!
I am assuming your Endo gave you medication for your hypothyroidism? If so, most likely he wants to see if the medication will improve your cholesterol numbers before trying anything else. For some, the cholesterol numbers will improve once the hypothyroidism is under control.
HDL is good cholesterol, and your 46 is very respectable. The higher your HDL the better. LDL is the bad cholesterol, so the lower the better. Triglycerides are a type of fat found in the blood. They are the easiest to lower by watching carb intake as well as alcohol and anything sugar related. You might want to check out the American Heart Assoc. website at [url]www.americanheart.org[/url] for more basic information.
Your cholesterol numbers really aren't that bad, but it can be a shock the first time you see they are out of whack. Although thyroid meds may help them, you might also want to consider making a few dietary changes. If you don't exercise regularly, aim for 30 minutes a day minimum of activity (like walking.) As one who also has a thyroid that is an underachiever

, I can tell you that a good diet and exercise help me manage that condition as well as my cholesterol. A good diet and exercise keeps my weight down, gives me energy, and makes me feel better overall.
Good luck!