The relationship between cholesterol levels and heart disease is significant, as high levels of low-density lipoprotein (LDL) cholesterol can lead to the buildup of plaque in arteries, increasing the risk of coronary artery disease and heart attacks. Conversely, higher levels of high-density lipoprotein (HDL) cholesterol can help remove LDL cholesterol from the bloodstream, reducing heart disease risk. Monitoring cholesterol levels is crucial for managing cardiovascular health.