I am no medical doctor, but 160 total cholesterol seems to be a bit on the low side. Low cholesterol for women is associated with higher mortality (ref. Norwegian HUNT study following over 50,000 people over 12 years).

Cholesterol tests are also not the most accurate. They can vary from day to day and from lab to lab.

That being said, if you have been low or lowish carb Paleo, the cholesterol increase is a possible (red) flag that should be investigated further, especially since you are hypothyroid. Paul Jaminet has some excellent posts on his blog that you should check out:

http://perfecthealthdiet.com/?p=4457 http://perfecthealthdiet.com/?p=2536

The glycogen content of the liver affects the conversion of T4 to T3 in the liver (where cholesterol is also involved). If you do not have enough glycogen to produce (enough) T3, the cholesterol will go up.

If you are on T4 meds instead of natural thyroid, you may be even more at risk, as the T4 only meds assume that you are able to convert T4 to T3 in the liver.

You might also want to check out this PHD article: http://perfecthealthdiet.com/?p=5528

Anyway, 220 is not terribly high, but you might want to check your free T3.

I wouldn't, for the following reasons:

1. You are only slightly above the upper level of the reference range for total cholesterol.
2. Your HDL is excellent -- 91 mg/dL is a good value.
3. Your LDL/HDL ratio is also excellent. The target is below 3.0.
4. Your triglycerides are nice and low.

What doesn't often get mentioned is that genes very strongly influence blood lipids. I have to work pretty hard to have good ones; by contrast, I have friends who seem able to eat almost anything and have total cholesterol values that never go above 170 mg/dL.

Your values look a lot like mine, actually, although the last time my TC was anywhere near 160 mg/dL, I was eating low-fat and like a bird :)

My only piece of advice would be to keep exercising and work on getting rid of the extra pounds.