High cholesterol levels can cause plaque to build up in the blood and blood vessels. Plaque can block or narrow the arteries and increase the risk of heart attack, stroke, and other cardiovascular issues.

Testing a person’s cholesterol levels is an easy way to check their risk of developing heart disease. If the results show that a person has high cholesterol, a doctor may prescribe medication, recommend lifestyle changes, or both.

This article explains how cholesterol tests work, how often people should get them, and what the results mean. It also discusses the risks of untreated high cholesterol and the treatment options.

What to expect in a cholesterol testShare on Pinterest
Robert Daly/Getty Images

A cholesterol test is also called a lipid profile. This blood test measures the amount of cholesterol and triglycerides in the blood.

This information can help doctors determine whether plaque has built up in a person’s arteries.

A complete cholesterol test measures the following four types of fats in the blood:

  • Total cholesterol level: This is the total cholesterol in a person’s blood.
  • Low-density lipoprotein (LDL) cholesterol: People often refer to this type as “bad cholesterol” because it can build up in the arteries, raising the risk of heart attack and stroke.
  • High-density lipoprotein (HDL) cholesterol: Doctors call this “good cholesterol” because it helps keep the arteries clear of LDL cholesterol.
  • Triglycerides: These are fats in the bloodstream that give the body energy. If the body does not use these fats, the body stores them. High levels can indicate a risk of heart disease and other health problems.

Risks of untreated high cholesterol

High cholesterol often produces no signs and symptoms, but the health consequences can be severe.

When there is too much cholesterol in the blood, it builds up in the arteries alongside fat and other substances, forming deposits called plaque. The accumulation of plaque narrows the arteries and reduces and slows the blood flow to the heart. If the blood supply to any part of the heart becomes blocked, a heart attack can occur.

Why is a cholesterol test useful?

A cholesterol test serves as a tool to assess the risk of cardiovascular disease, including heart attack and stroke.

The test enables a doctor to measure and analyze the levels of fats in the blood. If there is too much cholesterol in the blood, the doctor may recommend treatment to lower cholesterol levels and reduce the risk of heart disease.

Who should get one, and how often?

Everyone should get regular cholesterol checks, although the optimal frequency depends on age and certain health risk factors.

The American Heart Association (AHA) recommends cholesterol testing for most adults every 4–6 years, starting at the age of 20 years. This testing will continue as long as they have a low risk of stroke or heart attack. After the age of 40 years, a doctor will calculate a person’s risk and may suggest more frequent testing.

Some people have an increased risk of developing high cholesterol and may need additional testing. These individuals include:

  • people with a family history of heart disease or high cholesterol
  • anyone who had high cholesterol levels in a previous test
  • people with type 2 diabetes
  • individuals with excess body weight
  • those with reduced mobility or low physical activity levels
  • people whose diet is high in saturated and trans fats
  • people who smoke

The risk of high cholesterol increases with age. Up to the age of 55 years, females typically have lower LDL cholesterol levels than males on average, but their levels may increase after menopause.

Children should also undergo cholesterol tests. The Centers for Disease Control and Prevention (CDC) recommend testing a child’s cholesterol levels once at age 9–11 years and again between the ages of 17 and 21 years.

Cholesterol testing generally does not take place during puberty because hormones can alter the results of the test.

A cholesterol test can be fasting or nonfasting.

Most cholesterol tests require fasting, which means that a person should consume no food, drink, or medication for 9–12 hours before the test except water and possibly some other fluids if the doctor recommends them. Due to this requirement, most people choose to have their cholesterol test in the morning.

The doctor will advise the person beforehand if they need to fast. A nonfasting test will only show levels of total cholesterol. It will not show how much cholesterol is LDL or HDL.

During and after

A cholesterol test is a fairly simple procedure. It involves drawing blood from a vein, and the procedure is the same as that of most other blood tests.

Prior to drawing blood, a technician will examine the arm to locate a suitable vein and clean the area with antiseptic. They will then wrap a band around the arm, near where the puncture site will be, to help the vein fill with blood.

The technician will then insert a needle into the vein, and blood will collect in a vial. They will remove the band while the needle is still in place. When there is enough blood in the vial, the technician will remove the needle and hold a cotton swab on the insertion site to stop the bleeding. They may then cover the area with a small bandage.

After the test, there are no special considerations. Most people can continue with their day immediately after the cholesterol test and drive themselves home if necessary. It is possible that the needle insertion site may become infected, but this is extremely unusual, only occurring in very rare cases.

The results of the test will help an individual and their doctor decide whether the use of medication or changes to lifestyle habits may be beneficial.

The results will include several measurements in milligrams of cholesterol per deciliter of blood (mg/dl).

The CDC recommends aiming for the following levels of cholesterol and triglycerides:

Cholesterol and triglyceridesDesirable level
Total cholesterolBelow 200 mg/dl
LDL cholesterolBelow 100 mg/dl
HDL cholesterol At or above 60 mg/dl
TriglyceridesBelow 150 mg/dl

Having high cholesterol does not automatically mean that a person will develop heart disease. There are many ways to manage cholesterol levels and lower the risk of heart disease.

A doctor can recommend lifestyle changes and medications to help manage and lower high cholesterol.

Recommended lifestyle changes for high cholesterol include:

  • getting regular exercise
  • maintaining a moderate weight
  • avoiding or quitting smoking
  • following a diet that is rich in whole, plant-based foods and limits processed foods and saturated and trans fats
  • managing stress, where possible
  • aiming for 7–9 hours sleep
  • limiting alcohol consumption

Sugars and carbohydrates increase triglyceride levels. Limiting the consumption of sugar and processed carbohydrates while consuming plenty of high fiber foods may help reduce this risk.

A doctor may prescribe medication to help manage cholesterol levels. Options include statins, bile acid sequestrants, PCSK9 inhibitors, and other options specifically for people with a family history of high cholesterol.

Medication will be most effective if a person uses it alongside lifestyle and dietary recommendations for lowering cholesterol. Many people find that combining lifestyle measures with medication helps them manage their cholesterol levels.

Cholesterol is a substance that occurs naturally in the blood. Age, some health conditions, and certain lifestyle practices can increase cholesterol levels. If the levels become too high, a person may have an increased risk of heart attack or stroke.

Regular cholesterol tests can help a person understand their risk and, if necessary, take steps to reduce it. Anyone who has concerns about their cholesterol levels should speak with a doctor to arrange a test.