Normal levels for low-density lipoprotein, or LDL, are 129 milligrans per deciliter for people not at risk for heart disease, according to the Mayo Clinic. For others, normal levels are 70 milligrams per deciliter for those at very high risk and 100 milligrams per deciliter for those at high risk.
LDL is sometimes called bad cholesterol because it is a prime factor in heart disease. The Mayo Clinic explain that this cholesterol builds up in the arteries and causes blockages that make it hard for blood to get to the heart or brain, leading to a heart attack or stroke. Keeping levels of this cholesterol within a normal range lowers a person's overall risk.