Hello and thank you for your very basic question. It is very important for everyone to get regular physicals to stay on top of their health and cholesterol screening is often a part of that. One of the trickiest things about monitoring cholesterol is that high cholesterol has no symptoms. You will only know that is high if you have blood drawn and a doctor tells you. But it is essential to keep cholesterol under control to prevent things like heart attack and stroke. Lowering 'bad' or LDL cholesterol if the number is too high and raising 'good' or HDL cholesterol if low will help balance the total cholesterol number.
There are several risk factors for developing high cholesterol that include age, diet, obesity, lack of exercise, smoking and diabetes. Life style changes can help some improve their cholesterol numbers and others must take medication to manage it.
https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/symptoms-causes/syc-20350800
We wish you the best of health.