The first testament of mankind, "Rigveda" has its Upveda as "Ayurveda". Atharva Veda, one of the four Vedas, also talked about Ayurveda. With this, we can conclude, how old the Ayurveda is? Also, we got to know it is having its roots in India. Talking more about the mythological aspects, it is believed that God Brahma created Ayurveda and transmitted the knowledge to Daksha Prajapati (the son of Brahma originated from his right thumb). Daksha then passed the magical knowledge of Ayurveda to Ashwini Kumaras (twin Vedic gods). The series of events continues with the passing down of knowledge from Ashwini Kumaras to Lord Indra (The king of Heaven & Gods), and from Indra to his three disciples, namely Acharya Kashyapa, Acharya Bharadwaj, and Acharya Divodas Dhanvantari.
So, Ayurveda is not man-made, indeed this medicinal science is discovered by God itself. Moreover, it is the oldest science of medicines.
Ayurveda works with the doshas in the body. The main aim of Ayurveda is simply to balance the doshas and offer a healthy and disease-free life. The human body has three doshas, namely, Vata, Pitta, and Kapha. When all these three are in the right portion, then we lead a disease-free life. You will learn deeper about these doshas in the Ayurveda Teacher Training Course in Rishikesh.