Two wards at a Nottinghamshire hospital have been closed after patients were found to have the winter vomiting bug, norovirus.
Wards 33 and 34 at King's Mill Hospital have been closed to new admissions and visitors after 14 patients and six staff came down with the bug.
Norovirus causes nausea and diarrhoea and lasts about two days. It is easily passed on from one person to another.
Visitors with any symptoms of the virus should stay away from the hospital.
Elaine Overton, specialist nurse for infection prevention and control at Sherwood Forest Hospitals NHS Foundation Trust, said: "We want to protect our patients by restricting the chances of people spreading this infection.
"For this reason, regrettably, we are asking that people do not visit patients on Wards 33 and 34, unless absolutely necessary.
"Members of the public are reminded of the importance of not visiting hospital if they have any symptoms of diarrhoea and vomiting or flu-like symptoms."
Noroviruses affect up to one million people a year in England and Wales.