According to orthodox system of allopathic system of medicine, disease has particular set of some common symptoms, which are common to every patient of that particular disease. According to them, disease is caused when some unhealthy factors like some unhygienic, unhealthy environmental conditions, or some disease causing pathogens affects body or some contaminated food, water or air or some disease causing agents gain entrance inside body. They are culprits responsible for causing disease. So, this was about what is disease according to allopathy . Image Source - https://pixabay.com/en/close-up-drugs-medical-medicine-1853400/