Why do certain people crave heat and others avoid it? Why do some suffer from insomnia, while others suffer from excesive sleep? Why does one have difficulty maintaining weight, while another suffers from the opposite? The constitutional concepts and body types of Ayurveda explain many of the intrinsic physical and personality differences between us. "One person's medicine is another person's poison" becomes a profound reality through the understanding of Ayurvedic medicine. Ayurveda is a five thousand year old system of medicine that stresses the inherent differences in physiology and psychology. We will look at the constitutional types and the differing needs between them.