A high-density lipoprotein level of 60 milligrams per deciliter or higher can protect against heart disease, according to MedlinePlus. Because it is considered the good cholesterol, a higher HDL number is better than a lower number.
An HDL level below 40 milligrams per deciliter is considered a major risk factor for heart disease, notes MedlinePlus. A range between 40 and 59 milligrams per deciliter falls between the danger zone and the healthy levels, with patients at the higher end of the range having less risk of heart disease.
Physicians combine the HDL number with the low-density lipoprotein number to get the total cholesterol level, states WebMD. The LDL cholesterol is considered the bad type of cholesterol. Doctors use total cholesterol numbers to assess patients' risks for heart disease.