The rescue on Monday afternoon involved a challenging winch down to the casualty by a coastguard helicopter's paramedic.
The Inverness Airport-based helicopter could not be brought too close in case its downdraft blew the man and his fellow walkers off the ridge.
The walker was taken to hospital for treatment.
The alarm was raised at 14:25 on Monday after the man became unwell on Carn Mor Dearg.
He was airlifted to Torlundy and from there was taken to hospital by ambulance.
Scott Sharman, paramedic winchman, said: "It was an extremely steep ridge and we needed to make sure we kept at a safe distance because the downdraft could very easily have blown them over the ridge."
A walker had to be rescued from a 1,000m (3,500ft) ridge near Ben Nevis after he became ill.