Nurse Pauline Cafferkey is being transferred to hospital in London to be treated for a "late complication" from the Ebola virus.
Ms Cafferkey, 40, is being flown from Glasgow by RAF Hercules for treatment at the Royal Free Hospital.
It is the third time she has been hospitalised since contracting Ebola.
She was originally infected while working in Sierra Leone in December 2014 and spent almost a month in an isolation unit at the London hospital.
She was released after making a recovery but fell ill again in October last year and was again treated at the Royal Free for meningitis caused by Ebola.
At one point, the Scottish nurse was described as ''critically ill'' but was discharged in November and transferred to Glasgow's Queen Elizabeth University Hospital to continue her recovery and later returned home.
However, NHS Greater Glasgow and Clyde said on Tuesday Ms Cafferkey was in a stable condition at the hospital after "routine monitoring" identified a problem.
A spokesman for the Royal Free Hospital said: "We can confirm that Pauline Cafferkey is being transferred to the Royal Free Hospital due to a late complication from her previous infection by the Ebola virus.
"She will now be treated by the hospital's infectious diseases team under nationally-agreed guidelines.
"The Ebola virus can only be transmitted by direct contact with the blood or bodily fluids of an infected person while they are symptomatic, so the risk to the general public remains low and the NHS has well-established and practised infection control procedures in place.