An incapacity to work brought about by stress was diagnosed in two women aged 40 and 38. They were both in conflict situations at work and had psychological problems. They stopped working but remained tired and irritable. After being unfit for work for more than a year they were diagnosed with hyperthyroidism which was treated appropriately. They both recovered and resumed work. Hyperthyroidism can impair physical and mental functioning. Presenting symptoms may be confusing, specifically if work-related factors appear to be the obvious implication. In The Netherlands, employees who become ill, consult their general practitioner or a medical specialist, who are concerned with diagnosis and treatment. They also report to their employer's occupational-health department, where the physician focuses on work-related factors that may impair health and on assessment of disability. Communication between all parties should be optimal.