Types of diseases

Lesson 31: Environment and human health

Types of diseases

The main diseases suffered by by the people are classified as follows:

  • Deficiency diseases: they are the disorders caused by lack of specific essential substances such as vitamins, minerals, or amino acids in the diet taken by a person. Eg:
    Avitaminosis A, Anaemia, rickets and Osteomalacia, Teeth & gum diseases.
    Arthropodal and Helminthic diseases: disease caused by infestation with arthropod parasites eg : Malaria, filariasis, Helminthic diseases.
  • Communicable diseases: are also known as infectious disease. They spread from one person to the other, that is, a healthy person can catch it from a patient.
  • Eg : Dysentery & diarrhea, Gastroenteritis, enteric fever, infectious hepatitis, whooping cough, tuberculosis, measles, veneral diseases, leprosy.
  • Non-communicable diseases: Cancer, cardio-vascular diseases.
  • Water related diseases: Poor and erratic water supply and sanitation services and inadequate sanitation in public places such as schools, hotels, hospitals, health centers etc. are the main problems for spreading of diseases. Providing access to sufficient quantities of safe water, facilities for the sanitary disposal of excreta, and introducing sound hygiene-related behavior can reduce the morbidity and mortality caused by these risk factors.

There are 4 major types of water-related diseases:

  • Water –borne diseases: These are caused by dirty water contaminated by human and animal wastes, especially from urban sewage or by chemical wastes from industry and agriculture. Eg: Diarrhoea, dysentery, polio, meningitis and hepatitis A and E. Excessive levels of nitrates cause blood disorders and pesticides in drinking water cause cancer, neurological diseases and infertility.
  • Water-based diseases: Aquatic organisms that live a part of their life cycle in water and another part as a parasite in man, lead to several diseases. Eg: Guinea worm affecting feet and round worm affecting the small intestine.
  • Water-related vector diseases: Breeding of insects like mosquitoes in stagnant water cause malaria and filariasis.
  • Water-scarcity diseases: Poor sanitation and poor water supply leads to tuberculosis, leprosy, tetanus etc.
    Arsenic in drinking water is a serious hazard to human health. Drinking water that is rich is arsenic leads to arsenic poisoning or arsenicosis.
  • Water with high concentrations of arsenic results in problems such as colour changes on the skin, hard patches on the palms and soles, skin cancer, cancers of the bladder, kidney and lung, and diseases of blood vessels of the legs and feet. It may lead to diabetes, high blood pressure and reproductive disorders.

Last modified: Friday, 6 January 2012, 10:19 AM