Prevention is better than cure. There are four levels of prevention: primordial, primary, secondary, and tertiary. Primordial prevention aims to prevent risk factors from arising in a population. Primary prevention removes the possibility of disease by addressing risk factors before onset. Secondary prevention halts disease progression through early detection and treatment. Tertiary prevention focuses on rehabilitation and reducing impairments and disabilities for those with advanced disease. The strategies of prevention include health promotion, specific protection, early diagnosis and treatment, disability limitation, and rehabilitation.