Gender differences in fibromyalgia and other related syndromes.

Fibromyalgia syndrome is characterized by widespread musculoskeletal pain, fatigue, poor sleep, and tenderness on palpation at multiple sites called tender points. It occurs mostly among women; only about 10% of patients are men. Two recent studies showed that women had significantly more common fatigue, morning fatigue, "hurt all over," a greater total number of symptoms, as well as a greater number of tender points. Gender differences have also been reported in other related syndromes such as tension headache, migraine, irritable bowel syndrome, chronic fatigue syndrome, and temporomandibular disorder. Although the mechanisms of gender differences in these illnesses are not fully understood, they are likely to involve an interaction between biology, psychology, and sociocultural factors.