What does total cholesterol mean?

Total cholesterol is a type of fat and protein cholesterol in human blood. Generally, the total cholesterol in the human body comes from the daily diet. Eating too much fat food will easily lead to high total cholesterol, which can easily affect your health and cause some complications. You should pay more attention to prevention and eat more light foods.

Total serum cholesterol refers to the sum of cholesterol contained in all lipoproteins in the blood, including free cholesterol and cholesterol esters. In addition to coming from food, cholesterol in the human body can also be synthesized in the body by acetyl coenzyme A. The liver and small intestine of an adult can provide about 90% of endogenous cholesterol. The level of total serum cholesterol is affected by many factors such as age, family, gender, genetics, diet, and mental state. It is higher in men than in women, and lower in manual laborers than in mental laborers.

Since serum total cholesterol is closely related to cardiovascular and cerebrovascular diseases such as atherosclerosis, coronary heart disease, and stroke, the determination of serum total cholesterol has become a routine item in blood lipid analysis.

Clinical significance

1. Increase: Hypercholesterolemia has a clear relationship with the formation of atherosclerosis; lowering serum cholesterol reduces the incidence of coronary heart disease and stops the progression of atherosclerotic plaques. Serum cholesterol levels are affected by age, gender, etc. Except for familial hypercholesterolemia (FH), elevated serum cholesterol is more common in patients with nephrotic syndrome, hypothyroidism, diabetes mellitus, and biliary obstruction.

2. Reduce: intestinal malabsorption, liver disease, hyperthyroidism, anemia, severe infection, etc.

Normal reference range

The normal reference value of serum total cholesterol is 2.85~5.69mmol/L (110~220mg/dl).

1. Blood should be drawn after fasting for 12 hours.

2. The total serum cholesterol level is easily affected by many factors such as diet, age, and gender. Pay attention to identifying the reasons for the increase or decrease in the total serum cholesterol level.

Physiological functions

(1) Formation of bile acid: Bile is produced in the liver and stored in the gallbladder. It is then released into the small intestine and mixed with digested fat. The function of bile is to break down large particles of fat into small particles, making them easier to react with enzymes in the small intestine. At the end of the small intestine, 85% to 95% of the bile is reabsorbed into the blood, the liver reabsorbs bile acid and keeps it circulating, and the remaining bile (5X to 15%) is excreted from the body with feces. The liver needs to produce new bile acid to make up for the 5% to 15% loss, and cholesterol is needed at this time.

(3) Synthetic hormones: Hormones are chemical messengers that coordinate the metabolism of different cells in multicellular organisms. They participate in the metabolism of various substances in the body, including sugar, protein, fat, water, electrolytes and minerals, and are very important for maintaining normal physiological functions of the human body. Various hormones released by the human adrenal cortex and gonads, such as cortisol, aldosterone, testosterone, estradiol and vitamin D, are steroid hormones, and their precursor substance is cholesterol.