Our body is a huge storage of material, useful as well as waste. All these material is nothing but the conversion of food which we eat everyday. The material which is required to maintain and energize the body gets converted in various forms of Dhatus (Which gives structure to the body and do various functions). On the other hand,  waste material remain in the blood as well as in the body parts in the form of Doshas (Vat/Pitta/Kapha) or Ama (Toxic Material), which may get removed from the body in various ways through Urination, Defecation and Sweat on its own and sometimes through Vomits and in the form of Diarrhea. If such waste material is remain stuck in the body, it may start showing various symptoms and it remains for long time then it may cause chronic diseases or any silent diseases like Diabetes, Hypertension, Skin diseases and many more. 

Panchakarma is the process in which all these material is therapeutically  removed from the body without disturbing any body part. 

Pancha Means 5 and Karma means the process done on the body to remove toxic material