
Cholesterol is one of the three major lipids in the circulatory system. Cholesterol, along with triglycerides and phospholipids, binds to water-soluble proteins to move in the bloodstream. Cholesterol testing is part of the body’s lipid profile to measure the amount of fats in the body, thereby assessing the risk of cardiovascular disease.
Cholesterol in the body has two main sources
- Exogenous source: present in food. Each day, the intake of food provides about 50mg to 3g of cholesterol to the body. Under the action of lipase enzymes, cholesterol is hydrolyzed into fatty acids and absorbed with the help of bile acids. Some cholesterol-rich foods include meat, egg yolks, animal organs, etc.
- Endogenous source: the liver (accounting for 80%) and the intestines primarily synthesize cholesterol from acetyl CoA.
The Total Cholesterol test is used to measure the cholesterol level in the blood. This test is used to predict the risk of heart disease and stroke when the body is provided with excessive cholesterol, thus playing a crucial role in evaluating human health.

HDL & LDL
The Role of Cholesterol in the Body
Cholesterol plays various roles in tissues:
- It participates in the synthesis of cell membranes.
- It contributes to the synthesis of vitamin D.
- It is involved in the synthesis of sex hormones, corticoids, and glucocorticoids, as well as in the regulation of water and salt balance in the adrenal glands.
- It deposits in blood vessels, contributing to the formation of atherosclerotic plaques.
The Total Cholesterol blood test is used to evaluate the status of blood lipid disorders, assess the risk of atherosclerotic plaque formation, study liver function, and support the diagnosis of thyroid dysfunction.
The results of the Total Cholesterol test reveal the following
Blood is taken from a vein and then centrifuged to obtain serum for testing. Before the test, it’s advisable to fast for 8 – 12 hours and avoid alcohol for 24 hours.
The Total Cholesterol test is often ordered alongside other lipid panel tests, which include Triglycerides, HDL – Cholesterol (HDL – C), and LDL – Cholesterol (LDL – C).
- Total Cholesterol test:
- Reference range: 2.6 – 5.2 mmol / L. The ideal value is < 5.2 mmol/L: low risk.
- Cholesterol levels from 5.1 – 6.2: questionable results, potential health concerns.
- Cholesterol levels > 6.2: you are at high risk of developing atherosclerosis due to elevated blood cholesterol.
When Total Cholesterol is elevated while Triglycerides are within normal range, it suggests a simple elevation of blood cholesterol. When Triglycerides are elevated along with Total Cholesterol, it indicates a mixed lipid disorder. Conversely, when Triglyceride levels are 2 – 3 times higher than Cholesterol, it signifies endogenous Triglyceride elevation.

Results of Total Cholesterol Test
Causes of Cholesterol Level Changes
There are several factors that can lead to fluctuations in blood cholesterol levels.
Medications can impact the results, such as:
- Medications that increase blood cholesterol levels: sedatives, birth control pills, corticosteroids, lithium, and more.
- Medications that decrease blood cholesterol levels: estrogen, levothyroxine, metformin, and others.
Elevated blood cholesterol levels can result from:
- Diet high in cholesterol and fatty acids: consuming fried, fatty foods, fast food, and processed foods.
- Weight: individuals who are overweight or obese often have higher blood cholesterol levels. A body mass index (BMI) above 23 indicates elevated cholesterol.
- Regular exercise and physical activity can increase cholesterol levels.
- Gender and age influence: compared to men of the same age group under 50, women typically have lower cholesterol levels. However, after 50, women’s cholesterol levels tend to be higher than men’s.
- Unhealthy habits like smoking, alcohol consumption, or the use of stimulants also impact blood cholesterol levels and are risk factors for heart disease.
- Some medical conditions contribute to cholesterol changes, including: pancreatic dysfunction, renal insufficiency, gallstones, cardiovascular disease, diabetes, and more.
Reduced blood cholesterol levels can be seen in:
- Daily meals that don’t provide enough cholesterol to the body: certain cholesterol-rich foods should be included in the diet, such as various types of fish (salmon, tuna, etc.), eggs, cheese, yogurt, and dark chocolate.
- Immune-deficiency conditions like HIV/AIDS, hyperthyroidism, severe liver disease, anemia, or chronic blood loss.
- Impaired absorption in cases of bowel resection, malnutrition.
- Stress and tension can also affect cholesterol levels.
Who Should Undergo Blood Cholesterol Testing?
Total cholesterol testing helps detect and assess individuals at risk of developing arterial plaque, allowing for appropriate treatment approaches. Additionally, this test is useful for evaluating certain liver conditions.
The following cases are recommended for cholesterol testing:
- Everyone should have regular blood cholesterol testing to monitor their overall health status.
- Individuals who smoke or consume alcohol regularly.
- Patients with disorders related to lipid metabolism or other conditions such as liver, kidney, diabetes, or immune deficiencies.
Conclusion
In conclusion, understanding cholesterol and its impact on our health is essential. Monitoring cholesterol levels, maintaining a healthy lifestyle, and following medical recommendations are vital steps in preventing cardiovascular issues and maintaining overall well-being. Regular cholesterol testing plays a crucial role in early detection and proper management. By staying informed and proactive, we can significantly reduce the risk of heart-related diseases and lead healthier lives.

John Alen was born in 1971 and is a doctor in the healthcare and psychology fields with many years of experience. He is currently working at easyhealthylive.com, a leading health and psychology blog. Having studied at Y1 National Medical University named after IM Sechenov, John Alen is using his knowledge and experience to help improve the physical and mental health of people in the United States.