ABSTRACT
A 55-year-old man presents to his general practitioner (GP), complaining of lack of energy. He has become increasingly tired over the past 18 months. He works as a solicitor and describes episodes when he has fallen asleep in his office. He is unable to stay awake after 9:30 pm and sleeps through until 7:30 am. He finds it difficult to concentrate at work and has stopped playing his weekly game of tennis. He had an episode of depression 10 years ago related to the break-up of his first marriage. He has no current personal problems. He has had no other major illnesses. His brother developed type 1 diabetes mellitus at the age of 13. On direct questioning, he has noticed that he has become more constipated but denies any abdominal pain or rectal bleeding. He has put on 8 kg in weight over the past year.
