State and explain the four major factors, which are the causes of diseases. Please answer my question cuz I have my science exam tomorrow!!
Four major factors which are the causes of disease are :
(a) Infection by micro-organisms (bacteria, virus, fungi, protozoa) and worms; cause communicable diseases.
(b) Malfunctioning of body organs; non-communicable diseases like diabetes and heart diseases are caused by the malfunctioning of pancreas and heart respectively.
(c) Deficiency of one or more nutrients; goitre, marasmus and kwashiorkor are such diseases.
(d) Genetic factors present from the birth of the individual; haemophilia is a genetic disease.