Al-Tabari, inspired by Hippocrates, believes that miscarriage can be caused by physical or psychological experiences that causes a woman to behave in a way that causes the bumping of the embryo, sometimes leading to its death depending on what stage of pregnancy the woman is currently in. He believed that during the beginning stages of pregnancy, the fetus can be ejected very easily and is akin to an "unripe fruit". In later stages of pregnancy, the fetus is more similar to a "ripe fruit" where it is not easily ejected by simple environmental factors such as wind. Some of the physical and psychological factors that can lead a woman to miscarry are damage to the breast, severe shock, exhaustion, and diarrhea.