European countries need to rethink strategies for end of life care due to the ageing population, according to researchers in the Netherlands.
They said deaths from cancer and long-term diseases were a "considerable burden" on society and accounted for 42% of all deaths.
They warned that many would face pain, depression and anxiety before dying.
The findings were published in the medical journal BMJ Supportive & Palliative Care.
The team from Radboud University Medical Centre looked at death certificates from 4.8 million people from 27 EU countries in 2007.
Two million died of cancer, heart failure, diabetes, chronic liver failure, dementia, chronic respiratory disease, diabetes, neurological diseases and HIV/AIDS.
They said hundreds of thousands of people would face pain, depression, anxiety, confusion, fatigue and breathlessness before they died.
Policy makers need to develop long and short-term palliative care strategies to cope with the burden of these diseases, the authors said.
Tes Smith, social care programme manager of Macmillan Cancer Support, added: "A shift in the way end of life care is provided is vital.
"With the right support, 73% of people with cancer would prefer to die at home. Currently only 27% are able to do so.
"Free social care at the end of life and 24/7 community nursing for people in the last weeks and months of their lives would go a long way to making this choice a reality."