When we sleep well we take it for granted. One third of us will suffer from at least one of around seventy-five clinical sleep disorders at some point during our lives. These disorders may be undiagnosed, temporary, or influenced by factors such as pain, disease, or medicine. Sleep disorders dramatically affect quality of life and can be detrimental to health and wellbeing. There are eight types of sleep disorders listed in the International Classification of Sleep Disorder: insomnia, sleep-related breathing disorders, hypersomnia of central origin, circadian rhythm sleep disorders, isolated symptoms and normal variants, and other sleep disorders. ‘When sleep suffers’ charts the most common of these disorders.