According to studies conducted in several countries, between 17 and 32 per cent of the population suffers from insomnia. Epidemiological studies, concerning sleep disorders in Poland, carried out in 1996 showed that 24 per cent of the Polish population met the diagnostic criteria for insomnia. It is more common in women and among the elderly. Judging from the results of recent studies, one can assume that this problem is also growing in our country.