[Health consequences of shift work].

In humans many biochemical, physiological and behavioral processes occur in a rhythmic manner. Accumulating experimental and epidemiological evidence indicate that disturbances in biological rhythms could lead to unfavorable alterations in body function, thus exerting negative health impact. In industrialized countries, it is estimated that between 15 and 30% of the working population is involved in some kind of permanent night work and rotating shift work. Today, shift work is regarded as a significant occupational stressor which has marked negative effects on both health and well-being. This review surveys data on association between shift work and health problems, including sleep disorders, cardiovascular disease, peptic ulcer, metabolic syndrome, breast cancer and undesirable pregnancy outcome.