Cholesterol is a lipid found in your blood. Your body requires some cholesterol to function, but high cholesterol can clog the blood vessels with fatty deposits, restricting blood flow. More specifically, a doctor who suggests you lower your cholesterol really means to suggest that you lower your low-density cholesterol. High high-density cholesterol is beneficial. Most cholesterol blood tests also analyze levels of triglycerides, another blood lipid that you should keep at low levels.
LDL Cholesterol
LDL, or low-density cholesterol, is often referred to as bad cholesterol because it is linked to atherosclerosis, heart disease, hypertension and stroke. LDL collects on the walls of your blood vessels to form plaque. The plaque impairs your blood flow, and eventually tissue damage results when cells stop receiving enough oxygen-rich blood. According to the Mayo Clinic, a LDL level of less than 70 mg/dL is optimal, and 70 to 99 mg/dL remains in the healthy range. At 100 to 129 mg/dL, you have a borderline healthy LDL level, which crosses to borderline high at 130 to 159 mg/dL. A LDL level of 160 to 189 mg/dL is considered high, and190 mg/dL or above is considered very high.
Triglycerides
Triglycerides are another type of lipid that circulates through your blood. Your body stores unused calories as triglycerides, which the body later converts to energy between meals. The Mayo Clinic says that you may have high triglyceride levels if you regularly eat more calories than you use, especially if you tend to consume large amounts of refined sugars and fats. High levels of triglycerides can result in arterial plaque formation and heart disease. Often, an individual with high triglycerides will have high LDL and low HDL levels as well. According to the American Heart Association, ideally your triglyceride level should be less than 150 mg/dL. Your triglyceride level is considered borderline high if it falls in the 150 to 199 mg/dL range, high if it is between 200 to 499 mg/dL, and very high at 500 mg/dL or above.
HDL Cholesterol
HDL, or high-density cholesterol, is often referred to as good cholesterol because it helps prevent atherosclerosis, heart disease, hypertension and stroke. The American Heart Association cites two theories about how HDL works. Some medical experts claim that HDL cleans plaque from the arterial walls. Other experts believe HDL carries cholesterol to the liver, which expels it out of the body. The opposite of LDL and triglycerides, a high HDL is healthy. The Mayo Clinic advises that a HDL level that falls below 40 mg/dL is poor; between 50 to 59 mg/dL, the HDL level is borderline; and ideally you should maintain your HDL at 60 and higher mg/dL.
Total Cholesterol
Total cholesterol combines your triglycerides, LDL and HDL levels for a total cholesterol score. This score can be confusing because typically a high level reflects an unhealthy high level of LDL. In some instances, however, an exceptionally high HDL skews the total cholesterol level. Reviewing triglycerides, LDL and HDL individually provides a truer representation of your cholesterol health.
