What is Cholesterol in Blood Test? What is High and Low Cholesterol Level? Causes & Treatment?
- Health Garden
- Apr 14, 2024
- 8 min read
Updated: Jul 23, 2024
Total (complete) cholesterol test is a blood test that measures the amount of LDL (bad) cholesterol, HDL (good) cholesterol, VLDL and triglycerides in your blood.
It is also known as lipid panel or lipid profile.
Total cholesterol is calculated by the formula HDL + LDL + 20% triglyceride.
What is Cholesterol?
Cholesterol is a waxy, fat-like substance found in all cells in the body. It is produced primarily in the liver, but can also be obtained externally through food. The body needs some cholesterol to function properly. Cholesterol plays a role in the formation of cell membranes, the production of many hormones, vitamin D synthesis and fat digestion.
Since cholesterol is not soluble in water, it cannot pass into the blood on its own and cannot be distributed in the body on its own. LIPOPROTEINS are produced by the liver to help transport cholesterol. Cholesterol-carrying lipoproteins are divided into two main groups according to their functions: low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
What is LDL (Low-density lipoprotein)?
The job of low-density lipoprotein (LDL), also called bad cholesterol, is to carry cholesterol through your arteries.
LDL cholesterol itself is not actually bad. On the contrary, it is necessary for some body functions. It can only cause some health problems when there is more than necessary in the blood. If LDL cholesterol levels are too high, it can accumulate on artery walls over time. This condition is called atherosclerosis, and the resulting plaques are called cholesterol plaques or atherosclerotic plaques. In some cases, these deposits can break down and cause clot formation, which can disrupt the blood flow pattern in various organs, especially the heart. If a blood clot formed in this way blocks the vessels leading to the heart, it can cause a heart attack, and if it blocks a vessel leading to the brain, it can cause a stroke.
High cholesterol can also create a bile imbalance and increase the risk of gallstones. For these reasons, LDL is called bad cholesterol.
What is HDL (High-density lipoprotein)?
High-density lipoprotein (HDL), also known as good cholesterol, helps cholesterol return to the liver to be eliminated from the body. In this way, it prevents the accumulation of cholesterol plaques in the arteries. This is why it is called good cholesterol.
What is VLDL (Very low-density lipoprotein)?
VLDL is one of the protein-fat packages called lipoproteins, which are used to transport fat in the body. VLDL, produced by the liver, transports fats, especially triglycerides, to tissues.
VLDL is similar to LDL cholesterol, but LDL primarily transports cholesterol to tissues, while VLDL transports triglycerides.
Each type of lipoprotein contains a mixture of varying amounts of cholesterol, protein, and triglycerides. About half of a VLDL particle consists of triglycerides. VLDL and LDL are sometimes called "bad" cholesterol because they can contribute to the buildup of plaque in your arteries. This accumulation is called atherosclerosis. These plaques are a sticky substance made up of fat, cholesterol, calcium and other substances found in the blood. Over time, plaque hardens and narrows your arteries. Or it may cause clot formation. This limits the flow of oxygen-rich blood to your body. It can lead to coronary artery disease and other heart diseases.
There is no way to directly measure VLDL level. VLDL cholesterol is usually estimated as a percentage of your triglyceride value. However, if the triglyceride level is very high, it is difficult to estimate VLDL this way.
What is Triglyceride?
Triglycerides are a type of fat called lipids that circulate in your blood. The body converts the unused portion of the calories it obtains from food into triglycerides.
Triglycerides are stored in fat cells. These depots are located in fat tissue (adipose tissue). Triglycerides in these stores are used in situations of need such as between meals, activities that require a lot of energy such as sports, long-term hunger or hormone production. If more calories than needed are regularly consumed (especially high-carbohydrate foods), triglyceride levels may increase.
Triglycerides keep body temperature balanced, protect organs against external factors, strengthen the immune system, and meet the energy needs of cells and the body.
Triglycerides are important for health. However, high triglyceride levels in your blood can clog arteries, increasing the risk of heart disease and stroke. Therefore, triglyceride testing is used to understand your risk for heart disease, stroke, and other conditions involving your arteries, such as peripheral artery disease. The test is also used to help monitor heart conditions and treatments to reduce the risk of heart disease.
Triglyceride testing is usually done as part of a group of tests called a lipid profile. Lipid profile measures the level of triglycerides and cholesterol in the blood. If your levels of both LDL (bad) cholesterol and triglycerides are high, you may be at higher risk of having a heart attack or stroke.
Triglycerides and cholesterol are different types of lipids circulating in your blood. Triglycerides store unused calories and provide your body with energy. Cholesterol is used to make cells and some hormones.
What is A Normal Cholesterol Level in Blood Test ?
To obtain the most accurate results, you should fast for 12 hours before the blood sample is taken.
Total Cholesterol Level | Category |
Less than 200mg/dL | Desirable |
200-239 mg/dL | Borderline high |
240mg/dL and above | High |
LDL (Bad) Cholesterol Level | LDL Cholesterol Category |
Less than 100mg/dL | Optimal (best for your health) |
100-129mg/dL | Near optimal |
130-159 mg/dL | Borderline high |
160-189 mg/dL | High |
190 mg/dL and above | Very High |
HDL (Good) Cholesterol Level | HDL Cholesterol Category |
60 mg/dL and higher | Considered protective against heart disease |
40-59 mg/dL | The higher, the better |
Less than 40 mg/dL | A major risk factor for heart disease |
Triglyceride Level | Category |
Less than 150 milligrams per deciliter (mg/dL) | Optimal |
150-199 mg/dL | Borderline high |
200-499 mg/dL | High |
500 mg/dL or above | Very high |
A normal VLDL level is considered to be below 30 milligrams per deciliter (mg/dL). However, normal value ranges may vary slightly between different laboratories.
What is High Cholesterol Level in Blood Test?
High cholesterol value is a total cholesterol value of more than 200 mg/dL.
High cholesterol is evaluated at 2 different levels. Between 200-239 mg/dL is considered borderline high, and 240mg/dL and above is considered high.
If the cholesterol level is high, it can accumulate in the vessels as plaques and these deposits can break down and cause clot formation.
What Causes High Cholesterol Level in Blood Test?
Cholesterol is both taken from outside through food and synthesized by the body. Cholesterol increases for basically two reasons. The first is the high level of cholesterol taken into the body. Excessive consumption of foods of animal origin, frequent consumption of fast food and fried foods containing trans fats, and excessive use of animal fats cause high amounts of cholesterol to be taken into the body. The second is that the body produces too much cholesterol. Apart from these, the following factors also negatively affect cholesterol:
Being overweight or obese: Having a body mass index (BMI) of 30 or above increases the risk of high cholesterol.
Not exercising regularly: Exercising regularly helps increase the body's HDL (good cholesterol) level, while reducing the amount of LDL (bad cholesterol).
Using tobacco products: Smoking damages the walls of blood vessels, making it easier for fatty deposits to accumulate. It may also lower levels of HDL or "good" cholesterol.
Having family members with high cholesterol
Diabetes: High blood sugar increases the level of VLDL cholesterol type in the blood and causes the level of HDL cholesterol to decrease. High blood sugar also damages blood vessel walls.
Kidney diseases
Hypothyroidism
Genetic Causes: Genetic structure may prevent the process of removing LDL cholesterol from the blood from occurring effectively or may cause the liver to produce more cholesterol than necessary.
High Cholesterol Symptoms
Cholesterol can cause some symptoms due to its high level in the blood. In addition, it may manifest itself with some symptoms due to the diseases it causes. The most common of these symptoms can be listed as follows:
Yellow oil glands on the face and especially around the eyes
Chest pain
Weakness and fatigue
Pain and numbness in feet and legs
Dizziness
Delayed healing of wounds
Pale looking skin
Shortness of breath
Fat accumulation under the skin
Blemishes on the skin
Bruising in some parts of the body
Most cases of high cholesterol have a silent course, and therefore no obvious symptoms may be observed until the disease develops. This makes it more valuable to examine the cholesterol level in routine check-ups.
How to Treat High Cholesterol?
To treat high cholesterol, first lifestyle changes are made and, if necessary, drug therapy is started. A healthy lifestyle includes:
Healthy diet: Reducing or avoiding foods high in saturated fat and cholesterol can help lower blood cholesterol levels.
Regular physical activity: Studies have shown that physical activity can reduce LDL cholesterol and triglycerides and increase "good" HDL cholesterol. Before starting any exercise program, ask your doctor what level of physical activity is right for you.
Aiming for a healthy weight: Studies have shown that adults with overweight and obesity can lower “bad” LDL cholesterol and increase “good” HDL cholesterol by losing just 3% to 5% of their weight.
Stress Management: Research has shown that chronic stress can sometimes increase LDL cholesterol levels and decrease HDL cholesterol levels.
Quitting smoking: Quitting smoking can raise HDL cholesterol. Since HDL helps remove LDL cholesterol from your arteries, having more HDL may help lower LDL cholesterol.
Enough quality sleep: Sleep helps the heart and blood vessels heal and repair. The recommended amount for adults is 7 to 9 hours of sleep per day.
Limiting alcohol: Alcohol can cause weight gain. Being overweight can raise your LDL levels and lower your HDL levels. Too much alcohol can also increase your risk of heart disease because it can raise your blood pressure and triglyceride levels.
If diet and lifestyle changes are not enough, medications or other treatments to help lower cholesterol levels may also be prescribed. Statins are the most commonly prescribed medications for high cholesterol. These medications prevent the liver from producing more cholesterol.
What is Low Cholesterol Level in Blood Test?
Low cholesterol is less than 120 mg/dl of total cholesterol in the blood and is desirable.
Lower cholesterol levels may reduce the risk of heart disease. However, low cholesterol levels can also lead to some health problems.
What Causes Low Cholesterol Level in Blood Test?
Malnutrition: A diet that does not contain enough fat or fiber can cause your cholesterol levels to drop.
Liver disease: The liver is an organ that produces cholesterol. Liver disease can cause your cholesterol levels to drop.
Thyroid disease: The thyroid gland is an organ that controls your metabolism. Thyroid disease can cause your cholesterol levels to drop.
Some medications: Some medications, such as statins, are used to lower cholesterol levels. If these medications are taken too much, they can cause cholesterol to drop too low.
Genetics: If there is a family history of low cholesterol levels, you are more likely to have low cholesterol levels.
Low Cholesterol Symptoms
Possible symptoms of low cholesterol include:
Fatigue
Dizziness
Muscle pain
Memory problems
Depression
How to Treat Low Cholesterol?
Treatment for low cholesterol depends on the underlying cause. If it is low due to malnutrition, dietary changes may be made. If it depends on the medications used, the medication may be interrupted or the dose may be changed.