How low is too low for cholesterol number?

How Low to Go: Preferred total cholesterol is below 200, ideal is below 180 and for those with certain medical conditions lower is even better. The major focus of clinical research has been on LDL levels and it is believed that lower is better. How low is a good question. Many cardiologists would like below 100 for their patients and many studies support this. The "no go below" level hasn't been determined.

Unclear: Children are born with very low cholesterol levels, & do fine. Adults with mutations in genes that lead to low cholesterol levels (pcsk9) also do well with no issues. While ideal goals would be an ldl-c level <100 in most and <70 in very high risk patients, those with low hdl&high tg's might still have elevated apob or non-hdl-c levels. Further lowering might drive down cholest. Further and be ok.