
These diseases are not spread to other persons and are restricted only to those persons who are suffering from them as they do not infect other person by contact or carrier e.g.,diabetes, arthritis, cancer, heart diseases, haemophilia.
These diseases are not due to an external infection. Many of these diseases are due to nutritional deficiencies or unbalance e.g. obesity, marasmus, kwashiorkor. These are also called organic or metabolic disease.
Deficiency diseases :These diseases are produced by the deficiency of nutrients like proteins, minerals, vitamins, etc. e.g., Marasmus, kwashiorkor, anaemia, goitre, beriberi, pellagra, etc.
Allergies:These diseases are caused due to the hypersensitivity of the body to foreign substances like pollen grains, dust, silk, nylon, egg, fish, certain drugs, etc. The substances due to which allergy is caused are called allergens. e.g., Hay-fever, asthma, bronchitis, etc.
Cancers:Cancers are abnormal unwanted and uncontrolled tumour like growth of undifferentiated tissue in any part of the body.
Other diseases:These diseases occur due to various physical agents, such as heat, cold, humidity, radiation or due to mechanical agents, such as friction, accidents that cause injuries, sprain, dislocation of bones, fracture, etc.
