Nicholas is a 38-year-old retired jockey who attends regularly for prescriptions for timolol and latanoprost eye drops to control his longstanding glaucoma.

Today he presents complaining of increasing tiredness over the past month and, in his own words, “just generally slowing up and putting on weight alarmingly”.

He estimates he has gained 10kg in the past month, with no obvious change in diet to account for this.

He has been progressively less active over the month, due to fatigue, but is still managing to work full time as a horse trainer and trying to walk most days.