What is high cholesterol: symptoms, causes & prevention

Cholesterol is a fatty substance which is both produced by the liver and found in the foods we eat. Our bodies need cholesterol for many different functions, notably the maintenance of cell membranes and formation of vitamin D and hormones. However, if cholesterol levels get too high, fatty deposits accumulate in blood vessels and arteries which can lead to life threatening conditions such as a heart attack or stroke. Because high cholesterol usually has no symptoms, it can be very difficult to diagnose, and it may take a serious health problem to occur before you are aware of it. In this guide, we outline the possible causes and options for treatment of high cholesterol, as well as how to prevent your risk of heart disease and other health conditions caused by elevated cholesterol levels.

What is cholesterol?

Cholesterol is a lipid – a substance made from fats – which is required by our bodies to keep cells healthy and assist in hormone and vitamin D production. It is carried in the bloodstream by proteins, and this combination of substances is called a lipoprotein.

Cholesterol is commonly categorised into two groups: ‘good’ cholesterol and ‘bad’ cholesterol. This refers to the two types of lipoproteins present in the blood. These are:

  • High Density Lipoprotein (HDL) or ‘good’ cholesterol: This takes the ‘bad’ form of cholesterol back to the liver to be broken down and is therefore better to have a higher level of HDL.
  • Low Density Lipoprotein (LDL) or ‘bad’ cholesterol: If too much of this type is present in the blood, a fatty material called atheroma can build up in the walls of arteries and blood vessels, causing them to narrow and increasing a person’s risk for heart disease and stroke.

A higher level of HDL can keep the ‘bad’ LDL levels in check. Therefore, it’s ok to have a higher level of ‘good’ cholesterol, despite the common belief that any kind of high cholesterol is harmful.

What are the symptoms of high cholesterol?

There are no symptoms for high cholesterol which means many people do not know they are at risk until they experience a serious complication. A cholesterol test is the only way to measure the levels of LDL and HDL in the blood. You can find more about cholesterol testing and what the results mean in our Cholesterol Test guide.

If left untreated, high cholesterol can lead to heart disease and increase risk of blood clots to the brain and elsewhere in the body. You could be at risk of the following health conditions:

  • Atherosclerosis: narrowing of the arteries due to buildup of plaque
  • Angina: heart / chest pain
  • Coronary artery disease: blood supply to the heart is affected
  • Heart attack: blood supply to part of the heart is cut off
  • Transient ischaemic attack (TIA) or ‘mini stroke’: blood supply to the brain is affected
  • Stroke: blood supply to part of the brain is cut off

Given the link between high cholesterol and these conditions, it’s important to take measures to lower your LDL levels and therefore reduce your risk for these problems.

What are the causes of high cholesterol?

High cholesterol is caused by consuming too many lipids, and leading an unhealthy lifestyle.

It is possible for healthy individuals to develop high cholesterol, however the main risk factors for elevated cholesterol levels are:

  • Obesity: If you’re obese or overweight, you are more likely to have high cholesterol. If you have a body mass index (BMI) of 30 or above, you are more at risk for high cholesterol as well as associated health problems.
  • Poor diet and inactivity: Eating foods containing high saturated and trans fats, as well as red meat and full fat dairy can increase cholesterol levels. Regular exercise is also important for boosting HDL (‘good’ cholesterol) while making ‘bad’ cholesterol less harmful.
  • Smoking: Smoking cigarettes causes damage to the walls of arteries and blood vessels which makes it easier for fatty deposits to settle and for plaque to form. There is also evidence to suggest that smoking reduces levels of HDL in the bloodstream.
  • Age: As you age, your liver’s ability to remove LDL cholesterol diminishes. That’s why regular testing is especially important for older adults in order to monitor cholesterol levels.
  • Genetics: A family history of genetic conditions including premature coronary heart disease and familial hypercholesterolemia (FH) will increase an individual’s risk for high LDL cholesterol. You are also more likely to have high cholesterol if you are of South Asian origin.
  • Pre-existing health conditions: Some health conditions such as diabetes and high blood pressure can increase cholesterol levels. High blood sugar in diabetics can cause elevated levels of very low density lipoprotein (VLDL) and reduced HDL cholesterol. High blood pressure can form tears in blood vessels which can cause fatty deposits to accumulate more easily.

If you are part of an at-risk group, it might be a good idea to schedule a cholesterol test and speak to your GP or healthcare provider about monitoring your risk.

How to prevent and treat high cholesterol

While some risk factors for high cholesterol remain out of your control, there are several things you can do to reduce your cholesterol. Most preventative and treatment measures take the form of small lifestyle changes which are excellent ways to not only balance your cholesterol levels, but improve your health overall. These include:

  • Eating healthily: Consume plenty of cholesterol-friendly foods such as whole grains, fruit and vegetables. Incorporate a good amount of unsaturated fats into your diet, including oily fish (salmon and mackerel), olive oil, avocados, nuts and seeds. Reduce your consumption of foods high in salt, sugar, saturated and trans fats (processed foods, baked goods, fatty meat etc.)
  • Exercising regularly: Aim to do at least 150 minutes of exercise a week (2.5 hours). Go for brisk walks, try out cycling or swimming, but ideally do something you enjoy to make it easier to stick to a routine.
  • Cutting down on alcohol: Avoid consuming more than 14 units of alcohol a week. Set yourself several alcohol-free days throughout the week and avoid binge-drinking on the days you do have alcohol. If you’re finding it difficult to cut down, speak to your doctor or healthcare provider.
  • Giving up smoking: Although it’s not easy to quit, it’s one of the high cholesterol risk factors that can be controlled and stopping will definitely improve overall health and wellbeing. You can find some helpful tips on quitting smoking in our How to Quit Smoking guide.
  • Managing stress: There is some evidence to suggest that stress can also raise cholesterol, so managing your stress levels is also important. Exercise, meditation and a good night’s sleep are just a few of the ways to cope with stress, but if you are struggling, seek advice from a healthcare professional.

What is the normal cholesterol level?

The typical ‘normal’ level of cholesterol in men and women is around 5.0 mmol/L (millimoles per litre) or less: 3.0 mmol/L for LDL (‘bad’ cholesterol’). However, the results may vary depending on a number of factors including different individual circumstances and the type of test (fasting or non-fasting).

You can find out more about cholesterol testing, results interpretation and high cholesterol prevention here.

What causes low cholesterol?

It is normal for cholesterol levels to drop if you exercise regularly and eat healthily, but this isn’t a cause for alarm. It’s only when cholesterol starts to drop for no particular reason that you should seek medical attention.

There usually aren’t any symptoms of low cholesterol, but some possible risk factors include:

  • Having a family history of low cholesterol
  • Taking statins / being on other blood pressure treatment programmes
  • Having untreated clinical depression

The only sure way to diagnose low cholesterol is by getting a test. If you have lowered cholesterol levels and are experiencing symptoms of a low mood or any other uncharacteristic behaviour, speak to your doctor or healthcare provider.

How often should cholesterol be checked?

As mentioned above, high cholesterol typically doesn’t have any symptoms. It is therefore recommended that healthy adults should get a cholesterol test every 4-6 years, but those with cardiovascular issues or other health risks should get them more frequently.

A Bluecrest Wellness home test is a great way to measure cholesterol levels in between tests. Learn more about our quick and easy home test kits here.

What foods should you avoid if you have high cholesterol?

Lowering your cholesterol requires cutting down on sugary, salty, fattening and unhealthy foods, particularly those high in saturated and trans fats.

Some examples of foods containing unhealthy fats include:

  • Deep fried food
  • Processed food
  • Takeaway meals
  • Baked goods
  • Full fat dairy products
  • Butter
  • Fatty meat

Instead, you should eat a balanced diet consisting of the five food groups while incorporating healthy unsaturated fats into your diet.

How can I get tested for high cholesterol

Managing your cholesterol levels is crucial to staying healthy and preventing serious cardiovascular problems from developing. With the tips in this guide, you can stabilise your cholesterol and decrease the amount of LDL and triglycerides present in the bloodstream. Due to the asymptomatic nature of cholesterol-related diseases such as atherosclerosis, we’d still recommend that healthy adults have regular cholesterol screenings to monitor their risk.

A cholesterol test is offered as part of several Bluecrest Wellness Health Assessment packages. You can find out about the different types of tests and health screenings we offer here. Learn more about making healthy changes to your diet and lifestyle with guidance from our experts.