Dosha is often translated as the Sanskrit term for "humour", and it is one of the basic Principles of Ayurveda. Ayurveda (An Indigenous Indian medicine) uses a different concept of humours than the four humours of traditional Greco-Roman and European medieval medicine, which were fluids. Ayurvedic doshas are the manifestifestions of elemental forces in the physical body, and not physical substances in themselves.
Dosha also means "abnormal". There are three primary Doshas: Vata, Pitta and Kaphha. Their existence in the human body is considered individually, however two doshas can combine, as can all three doshas (this situation is known as Tridoshaj or Sannipataj).
The 3 main doshas are: Vata (combination of the space and air elements), Pitta (analogous to the fire element) and Kapha (combination of water and earth elements).