When you have high cholesterol, this means they you have a fatty substance called cholesterol in your blood. If you have too much cholesterol which can block your blood vessels, you can suffer from a heart attack and a stroke.
There are no symptoms for high cholesterol, but you can get a blood test to see if you have high cholesterol. If you do have high cholesterol as a result of your blood test, the doctor and nurse will then talk to you as to what you need to do to lower your cholesterol. This will include what you eat, exercise etc. They can also check the chances of you having a heart attack in the next 10 years based on your cholesterol levels, blood pressure, height and weight and age, sex and ethnicity. Lowering your cholesterol reduces the risk of suffering from a heart attack.