The Hippocratics blamed the womb for many of the women's health problems, such as schizophrenia. They described the womb as an independent creature inside the female body; and, when the womb was not fixed in place by pregnancy, the womb which craves moisture, was believed to move to moist body organs such as the liver, heart, and brain. The movement of the womb was assumed to cause many health conditions, most particularly that of menstruation was also considered essential for maintaining women's general health.