More than 600 people a day leave their jobs because of the demands of being a carer, says research from a charity.
The pressures of looking after an elderly, ill or disabled relative have made almost half a million people quit their jobs in the UK in the past two years, says Carers UK.
The report calls for more flexibility in the workplace for carers.
The charity's head, Helen Walker, says that 15% of the working population is "now working and caring".
The report estimates that almost five million people are trying to balance looking after relatives with working - up from about three million in 2011.
An ageing population has pushed this increase - but the report says not enough employers are offering flexibility over working hours or taking leave.