What causes high cholesterol?

The liver makes cholesterol, and the body also absorbs it from food. Genetics can affect how the liver removes cholesterol from the blood, so high results may occur even in someone who eats carefully. Foods rich in saturated or trans fats can raise harmful cholesterol in some people. Obesity, low physical activity, diabetes, kidney disease, and an underactive thyroid may also change cholesterol levels. Some medicines can contribute. High cholesterol usually causes no symptoms, so a blood test is needed to identify it and interpret the different cholesterol measurements together.

Share your full health history and medicines with a clinician, and ask whether the result should be repeated or checked alongside blood sugar, thyroid, liver, or kidney tests. Choose more fibre-rich foods, vegetables, pulses, and unsaturated fats, while reducing foods high in saturated fat. Regular activity and weight changes may help when appropriate. [Obesity](/conditions/obesity/) can be one contributor, but high cholesterol also occurs in people without obesity.

Book a routine appointment after an unexpected high cholesterol result, especially if close relatives had early heart disease or very high cholesterol. Seek emergency help for chest pressure, severe breathlessness, sudden weakness, or trouble speaking; these symptoms need urgent assessment regardless of the cholesterol result. Do not stop a prescribed medicine without discussing it with the prescriber.

Ask which cholesterol measure is raised, whether an inherited pattern is possible, what other tests are useful, and what lifestyle or medicine plan fits your overall cardiovascular risk.