People are being warned not to visit hospitals unless absolutely necessary after an outbreak of the winter vomiting bug.
Northumbria Healthcare NHS Foundation Trust is dealing with norovirus at hospital sites in Northumberland and North Tyneside, at a time when the system is already under pressure.
And visitors are being warned to stay away wherever possible in a bid to help avoid the virus spreading further.
Medical director Jeremy Rushmer said: "Every year we are affected by norovirus to one degree or another – this year is part of that pattern.
"The issue is that, given how fast it spreads, we often have to close whole areas; this at a time when the whole system is already under unsustainable pressure.
"It’s now severe enough that we are asking people to not visit our sites unless it is absolutely necessary. If someone you know has symptoms of norovirus do not visit – you risk causing harm to them, yourself and those close to you. If you have symptoms yourself – stay away. There is no cure; you just have to wait it out."
The virus usually starts with a sense of feeling sick, which is then followed by vomiting and watery, loose diarrhoea. Depending on the person, it can also include stomach cramps, general aches and pains, headaches and fever.
It is highly contagious and can spread at incredible speed in a number of ways. The risk of norovirus is most effectively reduced by good hygiene and using common sense.
For information on norovirus, how to avoid getting it and what to steps to take if you do, visit www.nhs.uk/conditions/norovirus/#what-to-do-if-you-have-norovirus