My Cholesterol is 7.8 and has always been high. Even at my fittest and healthiest, it never went down and my GP said it was probably hereditary, as my mother had high Cholesterol too.
My GP said, even though it was high, I was at lower risk of developing Heart Disease, as I exercised regularly, had a healthy diet and was a non smoker and drinker.
The main thing is to reduce the amount of saturated fats you consume and take part in regular cardiovascular exercise. Also, it would be an idea to get tested and if it is found to be high, you can then decide if you want to take Statins to reduce Cholesterol or try alternative natural remedies, like products containing Plant Sterols.