Question

what do you mean by disease describe the various causes of disease

Answer 1

A disorder of structure or function in a human , or plant , with symptoms , are known as diseases. There are numerous causes : 
Through bacteria / fungi / parasites
Through direct contact
through indirect contact 
through food / water 

Answer 2

Any physical disturbance in body is known to be disease and it's causes are :through contaminated water,by air,STDS, mosquito bites,etc...