Chronic disease

A chronic disease is defined as a ‘disease of long duration and generally slow progression’. The four major chronic non-communicable diseases – cardiovascular disease (CVD), cancers, chronic respiratory diseases and diabetes – cause the greatest burden of disease globally, whether measured as mortality (deaths) or morbidity (disability).

The WHO estimates that of the 58 million deaths from all causes in 2005, chronic diseases accounted for over 60 per cent (35 million). This is double the number of deaths from all infectious diseases, maternal/perinatal conditions and nutritional deficiencies combined. Only in sub-Saharan Africa is the burden of infectious disease greater than chronic diseases, but even here, the trend is towards a dual burden, with deaths from chronic diseases projected to overtake those from infectious diseases in the next ten years.

Many of the deaths from chronic diseases are premature – more than half of the deaths were in those aged under 70 – and women and men are almost equally affected.

The epidemic is largely driven by three major risk factors – tobacco use, poor diet and lack of physical activity. Many of the risk factors are themselves greatly exacerbated by underlying socioeconomic determinants, such as lack of education and poverty. These underlying determinants are a reflection of the major forces driving social, economic and cultural transition, including globalisation, urbanisation and aging populations.

The rising social and economic costs of chronic disease are jeopardising countries’ future development. The global recognition and response to this threat has not kept pace with the epidemic.