Progressive conditions
[ch 7: page 221]Someone with a progressive condition, for example, Type 2 diabetes, is protected once there is evidence that the condition has some adverse effect on their ability to carry out normal day-to-day activities, as long as the evidence shows that, in future, the adverse effect is likely to be substantial (Schedule 1, Paragraph 8 EA 10).
The question is not what might happen in the population as a whole, but what the medical evidence suggests is likely for a particular claimant (Taylor v Ladbrokes Betting and Gaming Limited [2016] UKEAT 0353/15/1612).
It would be unlawful disability discrimination for an employer to treat someone less favourably because they incorrectly assume that a mild condition is likely to worsen. This would be perceived disability (Chief Constable of Norfolk v Coffey [2017] UKEAT/0260/16). See below –Perceived disability.