Almost four in 10 nurses have treated patients whose health has been affected by malnutrition or food poverty.
And 41% have seen patients with health affected by inadequate or unsafe housing.
A major poll of more than 10,000 nurses and healthcare assistants around the UK also found that 21% have seen patients affected by a lack of heating.
The survey comes at the start of the Royal College of Nursing’s (RCN) annual congress in Glasgow.
The RCN said it is concerned these issues may be getting worse at the same time as funding is being cut back, and preventative work is being reduced.
Janet Davies, chief executive and general secretary of the RCN, said: “The NHS has evolved over the years into an excellent system for curing illness and treating its effects.
“But what this survey shows is the huge increase in ill health which could have been prevented.
“Lifestyle choices have a part to play, but many of the problems identified by nurses as affecting the health of their patients come down to the very difficult lives many of them lead.
“Inadequate or unsafe housing has a huge effect on health, as does overcrowding, food poverty, overwork, unemployment and family breakdown.
“Dealing with just one of these problems can take its toll on both mental and physical health, but the reality is that many people live with many of them.
“There is a widening divide between people who are living long and healthy lives and those who are struggling due to poor housing or poverty - and this inequality in itself is something that should not be tolerated.
“The RCN’s major worry is that efforts to tackle the issues and to help people live healthier lives are in danger of going backwards because of aggressive public health funding cuts.
“These issues are not new and efforts to tackle them go back many years. It is time that real, consistent progress was made in tackling them to avoid the consequences of profound social problems in the years to come.”