(a) Childhood risk 

There is now extensive evidence from many countries that conditions before birth and in early childhood influence health in adult life. For example, low birth weight is now known to be associated with increased rates of high blood pressure, heart disease, stroke and diabetes. 

(b) Risk accumulation 

Ageing is an important marker of the accumulation of modifiable risks for chronic disease: the impact of risk factors increases over the life course. 

(c) Underlying determinants 

The underlying determinants of chronic diseases are a reflection of the major forces driving social, economic and cultural change – globalization, urbanization, population ageing, and the general policy environment. 

(d) Poverty 

Chronic diseases and poverty are interconnected in a vicious circle. At the same time, poverty and worsening of already existing poverty are caused by chronic diseases. The poor are more vulnerable for several reasons, including greater exposure to risks and decreased access to health services. 

(e) Psychosocial stress also plays a role.