An outbreak of norovirus at the Queensway Carleton Hospital has affected 12 patients, the hospital said Friday evening.

The illness can cause nausea, vomiting, diarrhea, and stomach cramps. Other symptoms can include a low fever, aches and fatigue. Symptoms usually last 24 to 72 hours.

The outbreak happened in one rehabilitation unit and one surgical unit, the hospital said in a news release.

"The hospital is taking all possible steps to stop the transmission of the virus, prevent any further infection, maintain bed availability and provide the best possible care to its patients," the statement said.

The hospital's bed capacity is "severely restricted."

The statement noted that more patients require isolation during peak flu and viral seasons, which has an impact on the hospital's number of available beds.

The dozen patients showing symptoms have been isolated and are only allowed one visitor each. Common areas have been restricted, and visitors are being asked not to see patients at the hospital if they're not feeling well, and to wait 48 hours after  symptoms clear.

An similar outbreak of norovirus happened at the Carleton Place Hospital two weeks ago.