In his introduction to this series of articles from The Lancet, editor Richard Horton states that "While the political fashions have embraced some diseases - HIV/AIDS, malaria, and tuberculosis, in particular - any other common conditions remain marginal to the mainstream of global action on health. Chronic diseases are among these neglected conditions." He states that chronic diseases represent a huge proportion of human illness. They include cardiovascular disease (30% of projected total worldwide deaths in 2005), cancer (13%), chronic respiratory diseases (7%), and diabetes (2%).

This series of articles aims to fill a gap in the global dialogue about disease. He says that it is a surprising and important gap, one that health workers and policymakers can no longer afford to ignore. Without concerted and co-ordinated political action, the gains achieved in reducing the burden of infectious disease will be washed away as a new wave of preventable illness engulfs those least able to protect themselves. Let this series be part of a new international commitment to deny that outcome.

Articles from the series are:

• Preventing chronic diseases: how many lives can we save?
  by K Strong, C Mathers, S Leeder, R Beaglehole
  The first paper in the series reveals that, globally, around 58 million people will die in 2005; 35million of these deaths will be from chronic diseases.
• Preventing chronic diseases: taking stepwise action
  by JE Epping-Jordan, G Galea, C Tukuitong C, R Beaglehole
  In the second paper in the series, the authors outline a public health approach that can be used to reduce the burden of chronic diseases in low-income and middle-income countries.
• Responding to the threat of chronic diseases in India
  by KS Reddy, B Shah, C Varghese, A Ramadoss
  The third paper in the series outlines actions that need to be taken to curb the rising burden of chronic diseases in India, estimated to account for 53% of all deaths in the country.
• Preventing chronic diseases in China
  by L Wang, L Kong, F Wu, Y Bai, R Burton
  The final paper in the series on chronic diseases focuses on the prevention of chronic diseases in China, where 300 million men smoke cigarettes, 160 million adults have high-blood pressure, and an obesity epidemic is imminent.