A "significant number" of unwell patients have been admitted to the biggest hospital in the Highlands, the local health board has said.
Some admissions to Raigmore in Inverness have been delayed because of the situation.
NHS Highland has asked people to "make the right choice" in the care they need to help ease pressures on staff.
It said people with "less serious conditions" could contact their GP, pharmacist or NHS 24 for advice.
Raigmore has been described as "very busy" with emergencies and GP referrals cases all coming at same time.
NHS Highland said: "We are doing everything that we can to discharge patients who are well enough to leave as quickly as possible but you can also help us by helping your relatives or loved ones home.
"You can also help by making the right choice if you need healthcare advice or treatment and to avoid visiting the hospital if you have symptoms of diarrhoea, vomiting or flu.
"As staff prioritise dealing with the sickest patients, those arriving with less serious conditions are likely to face a longer wait."
The health board said staff were working "incredibly hard" to provide the best care possible to those that needed help most.
NHS Highland added: "If your needs are not a genuine emergency your pharmacist, GP or NHS 24 can help and may be able to see you more quickly."