According to the American Heart Association, 35.7 million Americans have a cholesterol level of 240 mg or higher, putting them at serious risk for heart disease. If you have a cholesterol level of 300 or more, this is cause for concern. Cholesterol by itself isn't a bad thing; everyone needs some amount of cholesterol to assist in hormone production, provide vitamin D and aid in digestion. When you have too much cholesterol, though, elevated risk of diabetes, heart attack or stroke comes into play.
Total Cholesterol Number
Your total cholesterol number is calculated by using three different numbers: low-density lipoprotetin, or LDL, high-density lipoprotein, or HDL, and triglycerides. To travel throughout the body, cholesterol is encased in a protein shell called a lipoprotein. This is what keeps the cholesterol and fat from sticking to your arteries. The difference in the thickness of the protein casing is what makes LDL different from HDL.
With LDL, the protein shell isn't very thick, thus allowing cholesterol to seep through and stick to your arteries. If cholesterol builds up in the heart, it can cause blockage and result in a heart attack. If outside of the heart, cholesterol or "plaque" buildup can become dislodged, traveling to the heart, lungs or brain. This can lead to a stroke.
The National Heart Lung and Blood Institute notes that less than 100 mg of cholesterol per 1 dL of blood is optimal; 160 to 189 mg is high, and 190 mg and above is very high.
HDL means the protein shell is thick, enabling it to carry the unused cholesterol to the liver. The liver then gets rid of the excess cholesterol, either by turning it into energy or through urination and defecation. Normal, or "heart-helping" HDL levels, according to the National Heart Lung and Blood Institute, are 60 mg and above; 40 mg or lower is considered a major heart disease risk.
Triglycerides also are a factor when calculating cholesterol. They are the chemical form of fat that is turned into energy. If the energy isn't used, it is stored in the body -- unlike the HDL, which is discarded. The normal range for triglycerides is less than 150 mg, while 200 to 499 mg is considered high, and 500 or above is very high.
Making healthy choices can lower your cholesterol from the high-risk 300 range to a less risky number. Smoking or maintaining a diet that is high in saturated or trans fats can play a huge part in contributing to your high cholesterol. Age has long been thought to be a factor, but according to a study published in the Journal "Gerontology," unhealthy cholesterol levels in older people may actually be related more to poor health than to age.