Blood cholesterol is one of the most important constituents of the blood/body. It has varied bodily functions, and it builds up healthy cells. It is an essential constituent of the cell wall (membrane), and if the level of blood cholesterol falls below normal, the walls of the red blood cells (RBC) are likely to rupture, thus causing a severe fall in haemoglobin (Hb).

Cholesterol mainly comes from the diet, i.e. from butter, ghee (saturated fat), egg-yolk, non-vegetarian food. Sea food/fish contains a low content of saturated fat. However, polyunsaturated fats like safflower, corn, sunflower, soybean, and cotton seed oils, etc do not give rise to serum cholesterol levels in the blood. These are recommended both for prevention and treatment of high blood cholesterol.

Cholesterol is also synthesized/made in the body. It has got limited excretion. Some is passed in faeces/bile, but is mostly retained in the body. The level of blood cholesterol rises as soon as the person eats.

The normal blood cholesterol level should be between 150-199 mg/ dl, and if it is more than 240 mg/ dl, it is considered a high level of blood cholesterol. Patients having a blood cholesterol level between 200-239 mg/ dl are borderline cases. Both in high and borderline cases, repeated check-ups of blood cholesterol are required.

However, those with a normal level of blood cholesterol must get their blood it checked-up, at least every five years, especially after the age of 40. In general, all persons above the age of 20 must get their blood tested to exclude high levels of cholesterol.

In children above 2 years of age, blood may be tested for cholesterol levels in case they have a family history of high blood .cholesterol/ coronary artery disease / stroke.

Blood cholesterol level may increase when a woman is on oral contraceptives or is pregnant. The level tends to decrease after the pregnancy is over, or after oral contraceptives are stopped. It may take even 5-6 months to come to normal levels. Screening for high blood cholesterol must be carried out through medical camps/house-to-house surveys to locate patients suffering from this malady, as they require immediate treatment. Significant importance is now being given to the levels of cholesterol among the general population. It is very important to know the level of blood cholesterol in a person at an early age

Blood cholesterol can be tested at any biochemical laboratory, after recommendation from the physician. One must talk to one's physician about the testing of blood cholesterol. The cholesterol level should be checked while fasting in the morning, and if a person takes alcohol, he should avoid it for at least 48 hours before the test. Above all, .the test must be carried out by an experienced biochemist. If the blood cholesterol level is high, it is advisable that a lipidogram be done.

High levels of blood cholesterol are dangerous for the body. They cause narrowing, and even blockage of the coronary arteries (blood vessels supplying the heart) and blood vessels supplying the brain, leading to heart attacks and strokes (paralysis, etc.) respectively. The chances of developing these diseases become higher if one has, in addition, diabetes, high blood pressure and obesity. The risk also increases if one has a family history of high blood cholesterol/heart attack. The danger is also greater in persons who are addicted to heavy smoking/tobacco chewing, and have sedentary habits. In females the risk is much more after menopause.

High levels of cholesterol may lead to gallstones, and may even be responsible for cancers.