The lives of many people in this world are undermined by chronic disease such as heart disease, stroke, cancer, chronic respiratory diseases and diabetes. Based on the definition of the US National Center for Health Statistics, chronic disease defined as a disease that persists for a long time; which lasts for 3 months or more.
Based on WHO data in 2008, chronic disease recovered 63 percent of deaths and is the leading cause of death worldwide. Death and chronic disease burden levels are similar in men and women and increase with age. The death and burden of disease rates are higher in low and middle income countries than in high income countries.
The most important risk factors for chronic disease are unhealthy diet / nutrition and excessive energy intake, physical inactivity, and tobacco use. Other risk factors such as alcohol use are at risk of liver damage : cirrhosis, pancreatitis and various cancers, including liver, mouth, throat, larynx and throat; infectious agents are responsible for cervical and liver cancer, and some environmental factors such as air pollution, which contribute to various chronic diseases including asthma and other chronic respiratory diseases. In addition, psychosocial and genetic factors also play a role.