Is handedness related to health status?

Handedness is the most important behavioural asymmetry due to its intimate association with the specialisation of the brain for language. It exists in 3 forms, namely right, left and mixed. Left-handers constitute the biggest minority group in the world and in many aspects they are in a disadvantaged position compared to right-handers. Numerous studies demonstrated association between left-handedness and different health problems ranging from learning disorders to breast cancer and decreased longevity. This paper reviews the relevant literature on the genesis of handedness and connection between handedness and health. Deviations from the "normal" pattern of braininess observed in some left-handers might contribute to developmental, cognitive and some mental disorders. However increased incidence of some of pathological conditions among sinistrals could hardly be explained by the "abnormal" pattern of braininess or by the action of a gene or genes responsible for handedness determination. Review of literature suggests that many of health problems of left-handers develop due to environmental, developmental and other mechanisms related to genesis of handedness.