My husband was diagnosed while serving in the RAF way back in 1979, so not sure if it’s different now or not!…
But at the time his basic choice was that they would allow him to remain serving in the RAF, but he would be confined to this country and a desk job or he could take a medical discharge.
He took the later, it took several months for the review for his medical discharge, and put before the medical panel who deemed that he was 19.5 points disabled, this meant that yes he could have a medical discharge from the RAF, but he couldn’t claim a RAF pension as you needed to be classed at the time as 20pt disable to keep your rights to a forces pension…
Hope this helps