The Claimant, who had been employed by the Respondent as a teacher until she resigned, claimed before the ET that she had suffered from a physical impairment, ultimately diagnosed as fibromyalgia, together with mental distress. She claimed that these impairments caused her to suffer a substantial and long-term adverse effect on her ability to carry out normal day-to-day activities. These claims were rejected by the ET, and the Claimant appealed on the grounds that the ET had not correctly determined the issues of "long-term" and "substantial" impairment.

The EAT held that the ET, in considering the issue of "long-term" impairment, had wrongly focused on the question of diagnosis, rather than impairment, and had failed to look at the reality of the risk that, on a broader view of the evidence available, it "could well happen" that the Claimant's impairments would last for at least 12 months; on the issue of "substantial" adverse effect, the ET failed to take into account evidence that was plainly relevant, and its decision could not stand.