High cholesterol

High cholesterol doesn't usually cause any symptoms. Over many years, though, it can increase the risk of cardiovascular diseases such as coronary artery disease, heart attacks and strokes.

Very high cholesterol levels that are caused by an inherited genetic defect sometimes lead to visible deposits under the skin. These can typically be seen as yellowish bumps on the Achilles tendon or above your eyelids. Swollen tendons in your hands can also be a sign of cholesterol deposits. Deposits in the eyes may appear as a light-colored ring at the edge of the iris. But many people who have high cholesterol due to their genes don't have any symptoms.

Cholesterol levels are mainly influenced by lifestyle factors. If high cholesterol is caused by an unhealthy lifestyle, it is called "acquired hypercholesterolemia." Habits that can lead to an increase in LDL cholesterol include:

• Eating a lot of saturated fatty acids and trans fatty acids
• Not getting enough exercise

People who are very overweight also often have high cholesterol. LDL cholesterol levels may go up a bit in women after menopause.

Sometimes, other medical conditions increase the risk of high cholesterol. This is particularly true for diabetes. But cholesterol can also increase due to rheumatoid arthritis, an underactive thyroid, and kidney or liver disease. Certain medications (like steroids or HIV drugs) can cause cholesterol levels to rise slightly, too.

Some people have high cholesterol due to their genes. Known as familial hypercholesterolemia, this condition is present from birth. It occurs when a person's parents pass on a mutated gene that stops the LDL cholesterol from being processed properly. This genetic defect can lead to very high cholesterol levels and greatly increase the risk of cardiovascular disease if it isn't treated.

The higher the LDL or total cholesterol levels, the higher the risk of cardiovascular disease. And the longer you have high cholesterol levels, the higher this risk: People who have high cholesterol at a young age are more likely to develop arteriosclerosis in the course of their lives.

Important: High cholesterol levels are just one of several risk factors. 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
• Older age
• Being male

The risk is also greater if a brother or your father had a heart attack or stroke before the age of 55, or if a sister or your mother had a heart attack or stroke before the age of 65.

You can assess your own risk with the help of a computer program (a risk calculator). This is best done together with your doctor. You can then use the results to decide with your doctor whether to take medication.

High cholesterol is fairly common. This is partly due to the fact that doctors now diagnose it at lower levels than in the past. According to a 2010 study by the Robert Koch Institute, more than half of all adults in Germany have total cholesterol levels that are above the optimal levels.

It is estimated that 0.3% of the global population have familial hypercholesterolemia.

To determine your cholesterol levels, the doctor takes a sample of blood which is then examined in a lab. Cholesterol levels are measured in milligrams per deciliter (mg/dl) and millimoles per liter (mmol/l). Various levels can be determined:

• Total cholesterol: This describes how much cholesterol someone has in their blood overall. High total cholesterol levels tend to be undesirable.
• LDL cholesterol (LDL-C): Cholesterol is transported in this form from the liver to other parts of the body, where it's used for many jobs. But any extra LDL-C might be deposited in blood vessels. High LDL-C levels are associated with a higher risk of cardiovascular disease because of this, so it's often referred to as “bad” or “unhealthy” cholesterol. Other types of cholesterol can be harmful, too, including VLDL cholesterol and lipoprotein (a).
• HDL cholesterol (HDL-C): Any extra cholesterol is carried in this form to the liver from the rest of the body. It is broken down in the liver and then leaves the body in bile. It is not clear what role HDL-C levels play in cardiovascular health. For a long time, high HDL-C levels were believed to have a protective effect. Because of this, HDL-C was referred to as "good" cholesterol. But more recent research has not confirmed that there's a protective effect.
• Non-HDL cholesterol: This is a measure of all the cholesterol in the blood apart from the HDL cholesterol. It is considered to be the best predictor of heart and blood vessel health because it includes LDL-C and the other harmful types of cholesterol. Risk calculators often use non-HDL cholesterol levels to determine people's risk of cardiovascular disease. Sometimes, the ratio of total cholesterol to HDL cholesterol is used instead (this is the total cholesterol divided by HDL cholesterol).

Triglyceride levels are often measured, too. These can also affect the risk of cardiovascular disease, but play a smaller role when determining this risk. Triglyceride levels may be higher in people with certain diseases, such as pancreatitis.

Doctors often use certain thresholds to describe different categories of cholesterol levels. But the risk of heart disease doesn't suddenly increase beyond certain cholesterol levels. Instead, it increases gradually: The higher the LDL-C or total cholesterol levels, for example, the higher the risk. The following table shows how cholesterol levels are often classified.

HDL cholesterol levels below 40 mg/dl (1.0 mmol/l) are also considered to be undesirable.

National and international medical associations sometimes use different thresholds. For example, some consider LDL-C levels of 116 mg/dl (3 mmol/l) or more to be too high. And different doctors sometimes use different thresholds when talking to their patients.

In Germany, people who have public health insurance can have a general health check-up every three years from the age of 35 (known as the Gesundheits-Check-up or Check-up-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 levels are measured too.

High cholesterol is one of several risk factors for cardiovascular disease, but not actually an illness in itself. So treatment shouldn't only be about lowering your cholesterol levels. It should aim to improve your overall heart and blood vessel health, too.

There are many things we can do ourselves to avoid high cholesterol levels 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 weight (if you are very overweight)
• Eating a low-salt diet (if you also have high blood pressure)

Cholesterol levels can also be reduced with medication. Drugs known as statins are typically used for this purpose. Most of the research on cholesterol medications has been done on statins. The findings show that they can lower the risk of cardiovascular diseases and increase life expectancy. The vast majority of people tolerate them well.

Ultimately, it's up to you whether you want to take medication as a preventive measure. Generally speaking: The more risk factors you have, the more likely you are to benefit from medication. You can assess your risk of cardiovascular disease together with your doctor and then weigh the pros and cons of taking cholesterol medication for yourself.

People who've already had a heart attack, stroke or other cardiovascular disease have a high risk of developing further heart problems. So they are advised to take statins. This is also true for people who have familial hypercholesterolemia.

There are also special products (like dietary supplements) that are sold with the promise that they will improve your heart health by reducing cholesterol levels. But there is no scientific proof that these products prevent heart disease: It is not enough to prove that a product reduces cholesterol levels. Instead, it's important to find out whether it actually reduces the risk of cardiovascular disease too – and that must be proven in a good-quality study.

Fish oil capsules containing omega-3 or omega-6 fatty acids have even been found to increase the risk of certain heart rhythm disorders ( atrial fibrillation). Because of this, some experts now advise people not to take them.

You can decide yourself what to do about high cholesterol levels and whether to take steps to prevent cardiovascular disease. How high is your personal risk and what level of risk do you find acceptable? How prepared are you to make changes in your life and would you consider medication? Some people want to keep any treatments and lifestyle changes as simple as possible. Others want to reduce their risk as much as they can, even if that involves more effort. How much you benefit from the treatment depends on your personal risk of developing related diseases.

When people are ill or need medical advice, they usually go to see their family doctor first. Information about health care in Germany can help you to navigate the German healthcare system and find a suitable doctor. You can use this list of questions to prepare for your appointment.