Cholesterol

Cholesterol is a valuable building block for your body. It is an important part of cells and is needed to make vitamin D and hormones like testosterone or estrogen, for example.

Only about a third of the cholesterol we need comes from the food we eat. Most of it is made in our bodies – mainly in the liver. Cholesterol is delivered to all of the cells in your body in the form of lipoproteins that travel in your bloodstream. Lipoproteins are tiny particles made up of protein and cholesterol "parcels." Your overall cholesterol levels (total cholesterol) are mainly made up of two types of cholesterol known as HDL cholesterol and LDL cholesterol. HDL stands for "high-density lipoprotein" and LDL stands for "low-density lipoprotein."

Total cholesterol is a measure of all the cholesterol in your blood. Abnormal levels may be a sign that your body can't metabolize (process) lipids properly. Together with the other blood lipid levels, your cholesterol levels can also be used to estimate your risk of cardiovascular disease.

In Germany, your cholesterol levels are measured as part of the general health check-up known as the Gesundheits-Check-up or Check-up 35. People with public health insurance can have this general health check-up every three years from the age of 35. Younger people (between the ages of 18 and 35) can have this check-up once.

To measure your cholesterol, the doctor takes a sample of blood – usually from a vein in your arm.

Meals hardly influence cholesterol levels, so you don't necessarily have to do the blood test on an empty stomach. But doctors usually recommend fasting beforehand anyway because other blood levels are often measured at the same time, and those may be affected by meals. If you're asked to come on an empty stomach, you shouldn't eat or drink anything other than still water in the 8 hours before the appointment.

The reference range values may differ from lab to lab because they sometimes use different test procedures. The following cholesterol levels can give you an idea, though:

If you have low total cholesterol levels, you won't usually need any further tests. Total cholesterol is rarely very low.

Very low total cholesterol can be caused by various medical conditions. For example:

• Overactive thyroid (hyperthyroidism)
• Liver diseases
• Chronic infections
• Cancer
• Malnutrition

If you take cholesterol-lowering drugs such as statins, a high dose can lead to very low cholesterol levels too.

Low cholesterol levels are usually harmless or even achieved on purpose as part of a treatment goal. But it still makes sense to have the cause of low cholesterol levels checked out by a doctor. They could be a sign of a serious illness or that you need to adjust your medication.

The medical term for too much cholesterol in your blood is "hypercholesterolemia." Generally speaking, the higher your cholesterol, the higher your risk of arteriosclerotic diseases such as peripheral artery disease (PAD), heart attack or stroke. But the total cholesterol levels don't mean that much when considered alone. Other blood lipid levels – like the proportions of HDL and LDL cholesterol – are important too.

Note: Cholesterol is just one of several risk factors. Your personal risk of cardiovascular disease can only be assessed if all the factors are considered together. Other important factors include smoking, your age, your biological sex and whether you already have other medical conditions such as diabetes, high blood pressure or kidney problems.

High total cholesterol levels can be caused by various things, like not getting enough exercise, eating an unbalanced diet or being overweight.

Sometimes cholesterol levels increase due to an underlying disease such as diabetes or an underactive thyroid gland. Chronic liver and kidney diseases can also have this effect. So can certain medications, like hormonal contraceptives, beta blockers and steroids.

Genes play a role in some cases: About 2 to 5 out of 1,000 people have a condition known as familial hypercholesterolemia. They already have high cholesterol in childhood due to an inherited genetic defect.

If you have high cholesterol, it's important to find out why. If it's caused by an illness, that illness should be treated.

People with high blood cholesterol might have a greater risk of cardiovascular disease. It can then be a good idea to lower the cholesterol levels – by how much mainly depends on their personal risk. The doctor can assess this risk based on certain risk factors and other blood levels.

You can do a lot yourself to lower your total cholesterol. Recommendations include

• getting more exercise,
• losing weight (if you're overweight),
• eating a balanced diet, and
• not smoking.

If that's not enough to make a difference or if you have a high risk of cardiovascular disease, cholesterol-lowering drugs such as statins may be considered. This medication is also recommended if your high cholesterol is caused by your genes.