Cholesterol levels are determined by two factors: diet and heredity. The human body naturally produces cholesterol, and certain foods raise the levels of cholesterol in your body. If your body overproduces cholesterol, this can lead to hereditary high cholesterol. If you consume certain foods or engage in other behaviours like smoking, high cholesterol can occur because of these lifestyle choices.
There are both good forms of cholesterol and bad forms of cholesterol. According to the American Heart Association, too little good cholesterol and/or too much bad cholesterol can increase your risk of heart disease, strokes and/or heart attacks.
Total Blood/Serum Cholesterol Level
The first number you receive, when given your cholesterol reading, is a total blood cholesterol level. A total blood cholesterol level of 200 mg/dl or below is considered to be optimal. This result, combined with adequate levels of the other cholesterols, means you have a healthy cholesterol level and have a comparatively low risk of heart disease, heart attack or stroke.
A total blood/serum cholesterol level of 200-239 mg/dl is a borderline high risk cholesterol level. Depending on your levels of bad and good cholesterol and triglycerides, your doctor may recommend a treatment and prevention program to help bring this cholesterol level back down to optimal levels.
A total blood/serum cholesterol level of 240 mg/dl or over is considered to be high risk. Lifestyle changes and/or medication are necessary to lower the risk of heart attack or stroke, which is twice that of those with optimal levels of blood cholesterol.
HDL (Good) Cholesterol Level
Because HDL is considered to be "good" cholesterol, a higher level of HDL is better than a lower level. An HDL level of 60 mg/dl or higher is considered to be the healthiest HDL level. For men, average HDL levels typically range between 40 and 50 mg/dl. For women, average HDL levels range between 40 and 50. HDL levels below 40 mg/dl in males and 50 mg/dl in females are considered to be high risk.
LDL (Bad) Cholesterol Level
LDL is bad cholesterol, so lower levels are considered to be healthy. The ideal LDL level is 100 mg/dl or below. An LDL level between 100 and 129 mg/dl is still considered to be average or relatively normal. An LDL level between 130 and 159 mg/dl is borderline high risk, an LDL level between 160 and 189 mg/dl is high risk, and an LDL level above 190 mg/dl is very high risk.
Triglyceride, although a fat and not a cholesterol, typically impacts cholesterol levels. Those with a high triglyceride level (200-499 mg/dl) or a very high triglyceride level (500 mg/dl or above) typically have a high level of bad cholesterol and a low level of good cholesterol.
Healthy triglyceride levels are considered to be 150 mg/dl or lower. Borderline levels are between 150 and 199 mg/dL.
Cholesterol levels which are too high can be lowered by diet, exercise, lifestyle changes and medication. Eating a healthy diet, exercising regularly and not smoking, can help to lower and maintain low cholesterol levels. If necessary, a doctor may prescribe medication to help manage high cholesterol that is caused by hereditary factors and/or cholesterol levels that have become too high to be reduced by simple diet and lifestyle modifications.