13. Horoscopes were used as part of medical astrology to determine the appropriate treatment of patients during the Medieval era
Medical astrology, known historically as iatromathematics, was a strand of medicine which associated a connection between certain parts of the body and the positions of celestial bodies; believing that these astrological phenomena and their placement in the solar system influenced the health and condition of the human body on Earth, many physicians adapted their treatment plans based on how they interpreted these other-worldly signs.
The twelve signs of the Zodiac, through unscientific and bizarre means, were calculated to govern specific parts of the body – for instance, the head was affected most by Aries, and the toe by Pisces – and accordingly during the ascendance of these cycles such conditions were superstitiously presumed to intensify. Accordingly, during the medieval era a patient would commonly be less examined physically than required to provide astrological information to be compared against a horoscope as a mode of diagnosis, treatment, and prognosis; in fact, during the 1500s many physicians of medieval Europe were legally mandated to examine a patient’s horoscope prior to treatment.