The ideal cholesterol number for adults above the age of 20 is 180mg/dl, according to the American Heart Association. The score for blood cholesterol levels are determined for adults by combining the amount of good cholesterol, bad cholesterol and 20 percent of the triglycerides found in the blood. Every adult older than 20 years of age should have their cholesterol levels measured every 4 to 6 years.
Maintaining healthy cholesterol levels helps to keep the heart functioning properly and also reduces the likelihood of suffering from a stroke or developing heart disease, according to the American Heart Association. It is important for a person to have their cholesterol levels checked throughout their life because it helps their doctor diagnose warning signs of possible strokes and heart attacks that may occur in the future.