It follows the Royal Sussex County Hospital in Brighton today declaring a critical incident because it is full, and the ambulance service reporting high demand.
Jane Farrell, chief operating officer at Western Sussex Hospitals which runs the trio of hospitals, said: “Following the cold snap, we continue to be extremely busy as we care for very high numbers of sick patients needing our support.
“Our hospital teams are working extraordinarily hard and doing all they can to treat people swiftly and return them back home, or to a more appropriate care setting, where their recovery will be better.
“It is not good for anyone to stay in hospital longer than is necessary and we would like to thank all the families and support services helping us to safely discharge patients as soon as they are ready to move on.”
At Brighton, the hospital has today discharged nearly 100 patients so it can concentrate on emergency procedures.
A spokesman for South East Coast Ambulance Service (SECAmb) added: “Along with the wider health service we continue to be extremely busy and, as ever, are working closely with our hospital colleagues to manage this increased demand.
“We urge everyone to remember that 999 should only be dialled in the event of a life-threatening or serious emergency.
“We are continuing to prioritise our most seriously ill and injured patients and patients not in a life-threatening or serious condition may have to wait longer than we would like.
“We’d also like to remind everyone of the alternatives to calling 999 or attending A&E including seeking help and advice from NHS 111, making an appointment with their GP or speaking to a pharmacist.”