A youth has been arrested after a medical professional was critically injured at a Tasmanian hospital.

Police were called to the North West Regional Hospital in Cooee, on the state's north-west coast, following reports someone had been wounded on Sunday.

They took a youth into custody a short time later.

The victim has been airlifted to the Royal Hobart Hospital in a critical condition.

Police say the incident was isolated and there is no threat to the wider community.

Investigators remain at the scene.

AAP