Cholesterol is a sterol molecule that is essentially a component of several hormones, forms the outer covering of nerves, and is required for cell wall synthesis. Cholesterol is primarily synthesized in the liver but we also get a large quantity from food. Several foods such as meat, dairy products, and eggs are rich in cholesterol.

Cholesterol is generally classified under various categories such as high-density lipoproteins (HDL), low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL).

LDL and HDL
Low-density lipoprotein (LDL) is often called “bad” cholesterol. It delivers cholesterol to the body. High-density lipoprotein (HDL) is often called “good” cholesterol. It removes cholesterol from the bloodstream. This explains why high levels of HDL cholesterol are good while high-levels of LDL cholesterol are detrimental for health. However, a medical opinion must be sought before reaching to any conclusion with regard to cholesterol levels.

Why is high cholesterol risky?
High cholesterol levels, called hypercholesterolemia, are a major risk factor for cardiovascular disorders. Abnormal cholesterol can also cause hypertension and stroke because it can deposit in the interior of the blood vessel and potentially reduce the space for blood flow. In several cases, the affected individual may not be aware of the abnormal cholesterol levels as they are often without symptoms.

Diagnosis and cholesterol range
Hypercholesterolemia can be easily diagnosed by measuring the cholesterol levels in the serum. Based on the lipid profile, an individual can be classified into normocholesterolemic or hypercholesterolemic. Normal ranges of various types of cholesterol are:

• Total cholesterol
  Below 200 mg/dl is considered normal. However, the values for HDL and LDL must also be considered before reaching to any conclusion.
• LDL cholesterol
  The ideal value is below 130 mg/dl
• HDL cholesterol
  60 mg/dl or more is good for preventing the heart attack risk.

Causes of high cholesterol
Several factors play a crucial role in deciding the cholesterol levels, some of them are as follows.

• Diet
  A poor diet selection which is high in animal or dairy products, saturated fat, cookies or bakery products can raise the total cholesterol levels.
• Obesity
  Obese individuals generally have abnormal serum lipid profile.
• Lack of exercise
  Exercise is important in balancing the lipid profile. Exercise increases the levels of HDL cholesterol. Living a sedentary lifestyle can worsen cholesterol levels.
• Smoking
  Smoking damages the walls of blood vessels and thus promotes fat deposition inside the vessels. Smoking also decreases HDL cholesterol levels.
• Diabetes
  Like smoking, diabetes also contributes to blood vessel damage, lowers HDL levels and raises the harmful LDL levels.

Signs
Common signs of hypercholesterolemia are angina or chest pain, atherosclerosis (deposition of lipid in blood vessels and subsequent blockage leading to stroke), and pain in the legs when the blocked blood vessels are unable to provide sufficient blood to legs.

Cholesterol is an essential molecule for the survival of the body. But high bad cholesterol levels are detrimental to health because they can block the blood vessels and can cause cardiovascular disorders. Sedentary lifestyle and bad food habits are some of the main causes of abnormal cholesterol levels.