Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 2

Chronic diseases are mainly caused by what general factors?

Step 1 of 3

Chronic disease epidemiology has been changed over the years due to improvements in the supply of safe drinking water, appropriate waste disposal, clean housing and regulation of food handling. The improvements in the public welfare programs have greatly increased the life expectancy rates over the years. There is a shift from infectious to noninfectious conditions explaining most illness and deaths throughout the world.

Nowadays, the chronic illnesses are not due to infectious agents because of improved public welfare systems; rather, these are majorly of noninfectious and non-communicable causes. A chronic disease is less severe than the acute diseases but lasts longer and in a continuous fashion. The pathological changes occurring before the clinical manifestations appear are relatively of longer durations. This time is called as latency period.