High cholesterol

At a glance

  • High blood cholesterol can increase the risk of cardiovascular disease but it isn't the only risk factor.
  • Whether or not it’s worth taking statins (cholesterol-lowering medication) depends on whether you have other risk factors too.
  • Sometimes, high cholesterol is a genetic disorder. Then doctors usually recommend statins.
  • There are lots of things you can do on your own to keep your heart and blood vessels healthy, including getting enough exercise, not smoking and eating a healthy diet.
  • Fish oil capsules with omega-3 fatty acids don’t prevent high cholesterol, and they can actually cause harm.

Introduction

Photo of a patient and doctor
PantherMedia / Alexander Raths

Many people worry about their cholesterol because high in the blood can increase the long-term risk of cardiovascular disease.

Cholesterol is an essential building block in all of our body's tissue, and it plays a key role in many parts of the metabolic process. It makes its way through the bloodstream in small "parcels," moving from one organ to the next. Generally speaking, there are two types of cholesterol: LDL cholesterol, which increases the risk of cardiovascular disease, and HDL cholesterol, which does not. People whose LDL cholesterol exceeds a certain level or who generally have a lot of cholesterol in their blood are considered to have high cholesterol (“hypercholesterolemia”).

In most people, alone don't say very much about their risk of cardiovascular disease because they're just one of several risk factors. You can only get a good idea of your personal risk of conditions like heart attacks or strokes if you take all of these factors into account. This can also help when deciding whether to take medication or not.

Symptoms

High cholesterol doesn't usually cause any symptoms. But if someone has high cholesterol over a period of many years, it can increase their risk of cardiovascular disease – such as angina, heart attacks and strokes.

Very high that a person has inherited can sometimes cause cholesterol to build up under the skin. This usually takes the form of yellowish bumps on the Achilles tendon or above your eyelids. Swollen tendons in your hands can also be a sign of cholesterol under the skin. In the eyes it may appear as a light-colored ring at the edge of the iris.

Causes

Your mainly depend on your lifestyle. Habits that can lead to an increase in LDL cholesterol include:

  • Eating lots of saturated and trans fatty acids
  • Not getting enough exercise
  • Smoking

People who are very overweight also often have high cholesterol. If the condition is due to one of these causes, it's called acquired hypercholesterolemia. LDL cholesterol may go up in women after menopause.

Sometimes, other conditions increase the risk of high cholesterol. This is particularly common in people with diabetes. But it can be caused by rheumatism, an underactive thyroid and kidney or liver disease too. Taking certain medications (like steroids or HIV drugs) can also make your go up somewhat.

Some people are born with high cholesterol due to their genes (this is called familial hypercholesterolemia). This happens when a person's parents pass on a mutated gene that stops the LCL cholesterol from being processed properly. Usually, the gene is passed on by only one parent (heterozygous familial hypercholesterolemia). If both parents pass the genetic defect on (homozygous familial hypercholesterolemia), the effect is greater. But this is extremely rare.

As people who have familial hypercholesterolemia have very high cholesterol values, the recommended treatment is to take cholesterol-lowering medication.

Risk factors

Generally speaking, the higher the LDL or total cholesterol level, the higher the risk of cardiovascular disease. But high cholesterol isn't the only risk factor. Many other things can have an influence. The risk of cardiovascular disease can only be properly assessed if all the factors are considered together. Other important risk factors include:

  • High blood pressure
  • Diabetes
  • Smoking
  • Age
  • Gender (men's risk is higher)

The risk is also greater if the person has a brother or father who had a or stroke before the age of 55, or if they have a sister or mother who had a or stroke before the age of 65.

You can assess your own risk using risk calculation software. This is best done with the help of a doctor. You can then use the results to decide with your doctor whether it's worth it to take medication.

Prevalence

High cholesterol is fairly common. This is partly due to the threshold levels doctors use for . According to a 2010 study by the Robert Koch Institute, more than 50% of adults in Germany have a cholesterol level above the current threshold.

Some experts criticize this threshold level because it means that a large number of people are considered to have a health problem. With the previous standard threshold, only 20% of adults would be diagnosed as having high cholesterol.

It is estimated that 0.2 to 0.5% of the global population have familial hypercholesterolemia.

Diagnosis

You can have a blood test done to determine your . Having a meal beforehand doesn't affect your cholesterol much so you don't really have to do the test on an empty stomach. Because other levels that might be higher after you eat are measured in your blood too, your doctor will usually recommend that you don't eat anything (or drink certain things) before your blood is taken. If you're asked to come to the test on an empty stomach, you shouldn't eat anything or drink anything other than unsweetened tea, coffee or water in the 8 to 12 hours before the test.

The test results usually distinguish between two types of cholesterol – LDL and HDL.

  • LDL cholesterol transports cholesterol from the liver to other parts of the body where it's used for various jobs. But any excess LDL can be stored. High LDL are associated with a higher risk of cardiovascular disease, which is why it is frequently referred to as “bad” or “unhealthy” cholesterol.
  • HDL cholesterol absorbs excess LDL and takes it to the liver, where it's broken down and leaves the body through the bile. A high HDL level is likely to have a positive effect on a person's risk of cardiovascular disease, which is why it is frequently referred to as “good” or “healthy” cholesterol.

The test results will also show your “total cholesterol”. This describes how much cholesterol someone has in their blood overall. High total tend to be unfavorable.

People are diagnosed with hypercholesterolemia if their total cholesterol or LDL cholesterol is above a certain threshold. Cholesterol levels can be measured in two different units: either as milligrams per deciliter (mg/dl) or as millimoles per liter (mmol/l). The current threshold levels are:

  • Total cholesterol: 200 mg/dL (5.2 mmol/L)
  • LDL cholesterol: 130 mg/dL (3.4 mmol/L)

HDL below the following thresholds are also considered to be unfavorable.

  • HDL cholesterol: 40 mg/dl (1 mmol/L) in men and 50 mg/dl (1.3 mmol/L) in women

Screening

In Germany, people who have statutory health insurance are entitled to a general health check-up every three years from the age of 35. Younger people (between the ages of 18 and 35) can have the check-up once.

The aim of the check-up is to detect early signs of and risk factors for cardiovascular disease, diabetes and kidney problems. It involves things like having your blood pressure taken, and blood and urine tests. Your cholesterol will also be measured.

Treatment

High cholesterol is one of a number of risk factors, but not actually an illness in itself. So treatment shouldn't only aim to lower the person's . It is important to take their overall cardiovascular (heart and blood vessels) health into account.

There are lots of things we can do on our own to avoid poor and keep our cardiovascular system healthy. They include the following:

  • Not smoking
  • Reducing the amount of saturated fats and trans fats in your diet
  • Getting enough exercise
  • Losing a little weight if you're very overweight
  • Eating a low-salt diet if you also have high blood pressure

People who have a significantly increased risk of cardiovascular disease, due to a coronary heart disease for example, can benefit from medication that reduces . But the benefits for people who don't have a cardiovascular disease are limited – especially if they only have high cholesterol but no other risk factors for instance. So it's a good idea to talk to your doctor about the advantages and disadvantages. Ultimately, it's up to you whether you want to take medication as a preventive measure.

If you do decide to take medication, you'll be prescribed . Of all options available, most research has been done on . The findings show that they can lower the risk of cardiovascular diseases and increase life expectancy. They are also well tolerated by the vast majority of people.

People who've already had a , stroke or other cardiovascular disease have a high risk of developing further heart problems. So are a recommended treatment for them as well as for people who have familial hypercholesterolemia.

There is no proof that dietary supplements containing omega-3 or omega-6 fatty acids provide protection against cardiovascular disease. But there is that fish oil capsules containing omega-3 fatty acids can increase the risk of an irregular heartbeat (). As a result, some experts now advise against taking them.

Please note that, when considering the benefits of medication, it isn't enough to look at how they affect cholesterol levels. Treatments can only be considered well tested if researchers have also looked at whether they actually prevent heart disease.

Abdelhamid AS, Brown TJ, Brainard JS et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev 2020; (2): CD003177.

Chou R, Dana T, Blazina I et al. Statin Use for the Prevention of Cardiovascular Disease in Adults: A Systematic Review for the U.S. Preventive Services Task Force. (AHRQ Evidence Syntheses; No. 139). 2016.

Cordon A, de Meester C, Gerkens S et al. Statins for the primary prevention of cardiovascular events. (KCE Report; No. 306). 2019.

Curfman G. Omega-3 Fatty Acids and Atrial Fibrillation. JAMA 2021; 325(11): 1063.

Hooper L, Al-Khudairy L, Abdelhamid AS et al. Omega-6 fats for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev 2018; (11): CD011094.

Mihaylova B, Emberson J, Blackwell L et al. The effects of lowering LDL cholesterol with statin therapy in people at low risk of vascular disease: meta-analysis of individual data from 27 randomised trials. Lancet 2012; 380(9841): 581-590.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on February 7, 2022
Next planned update: 2025

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Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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