People with sickness and diarrhoea are being urged to stay away from Stoke Mandeville Hospital to prevent the spread of a winter bug.
The large number of people going to hospital with respiratory illnesses and norovirus is putting extra pressure on services at a busy time of year.
People experiencing symptoms are being requested to think twice about visiting, unless they are seriously ill.
The Bucks Healthcare NHS Trust, which runs the hospital, said in a statement: “This common winter illness spreads from person to person and we need to ensure, as far as possible, we protect our patients and staff.
“Until you have been symptom free for 48 hours, please do not visit friends and relatives at the hospital.”
The trust said sick people should consider other options, such as the minor injuries and illness unit, their GP or pharmacist before coming to hospital and reminded people that A&E should only be used by those who are seriously unwell or critically injured.
It said: “We recognise that the high number of people being admitted onto our wards are unwell and need our services.
“However, we need to ensure that other services across the hospital, such as A&E, are working in the best possible way to support patients being seen by the right people at the right time.
“The trust has plans which are put in place when we are busy to ensure that patients continue to receive high quality care.
“This includes communicating with the public, liaising with our health and social care partners, and utilising additional staff, where necessary.”