Homeless people are likely to die 30 years younger than the national average, a study has suggested.
People living on the street will, on average, die aged 47, compared to the national average of 77, researchers from the University of Sheffield said.
The most common causes of death are alcohol and drug addiction - accounting for a third of all deaths, according to the study commissioned by homeless charity Crisis.
The research, which examined the homeless population in England, found that those living on the street are also three-and-a-half times more likely to commit suicide than the general population.
The charity said that homeless people are not getting the help they need from the health service.
People living on the street should have easy access to register with GPs and should not be discharged from hospital without accommodation and support.
Crisis chief executive Leslie Morphy said: "Homeless people are amongst the most vulnerable in our society and it is clear that despite significant investment in the NHS, they are not getting the help they need to address their health issues.
"The Government and health services must do more to improve the health of single homeless people and ensure they can access mainstream and specialist services. If they don't, then we fear homeless people will continue to die much younger than the general population."