Human Diseases


Table of Contents

Communicable Diseases
Prevention and Control
Important Questions

What is a Disease?

The diseases can be simply defined as a disturbance in the normal functioning of the body, among which few affects only to the particular organ system and some affect the entire body of an organism. There are numerous diseases which vary in their signs, symptoms, and causes. Pathology is the branch of medicines which mainly deals with the study of disease, the nature of diseases, its cure, diagnosis, etc.

Also Refer: Diseases 

As per the medical records, there are more than 20,000 of human diseases, which affect more than millions of people every year.

Let us study certain communicable human diseases along with its causes and preventions.

Communicable Diseases

Common Diseases

A disease, which spreads from one person to another person, is termed as the communicable disease. It is also referred to as infectious diseases or transmissible diseases.

Also Read: Communicable Non Communicable Diseases

Causes Of Communicable Diseases

The agents causing communicable diseases include Virus, Bacteria, protozoa, and Fungi.



These microbes are small infectious agents which are present in food, air and in the water. They penetrate very easily into our body through the mouth, nose, cuts, injuries, scratches on the skin from the environment (from the soil, water, and air) and other infectious agents and causes severe infections which may also lead to the person’s death. Viral infections can be easily transmitted from person to person.

AIDS, Polio, Measles, Influenza are a few examples of infections caused by a virus.



There are millions and billions of beneficial and harmful bacteria present all around us. Few among them are present both inside and outside our body always, by protecting our body from the disease-causing microbes. These bacteria are called beneficial bacteria. The other group of bacteria, cause harm by entering into our body. These bacteria generally, engulf, reproduce kill the protective bacteria and cause harm to the host cells by releasing toxins. Tuberculosis, Whooping cough, Typhoid, Cholera, are a few examples of infections caused by bacteria.



They are single-celled, microscopic, eukaryotic organisms. Malaria and other immune system disorders are few examples of infections caused by the protozoan.



They are threadlike parasites, which cannot synthesize their food and feeds on other organic material in which they live in. Ringworm, Athlete’s foot are a few examples of infections caused by fungi.

There are other agents, who act as a carrier or vectors and they carry the disease-causing microorganisms and spread from one person to another person. These vectors include mosquitoes, rats, house flies, etc.

Read more about: Microbes

Control and Preventions for Communicable Diseases

Listed below are a few precautions, which should be carried to avoid infection and other spreading diseases.

  • Drink only boiled and filtered water.
  • Maintain proper hygiene in the food which we eat.
  • Maintain cleanliness around us.
  • Keep our body clean and tidy by having a regular bath.
  • Wear clean and ironed clothes.
  • Avoid the entry of vectors like mosquitoes, rats, house flies, cockroaches by spraying insecticides.
  • Disinfectants and other antiseptics can be used to destroy the microbes.
  • Fish plays a vital role in destroying mosquitoes and their larvae by eating them. So by introducing fish aquarium in our home, we can prevent mosquitoes from transmitting diseases.

There are many diseases which develop from environmental problems, through nutrition deficiency, blood-related issues, chromosomal disorders, and so on.

Also Refer: Diseases Caused By Microorganisms

Important Questions on Communicable Diseases

  • What are antibiotics?

Antibiotics are defined as drugs or strong medicines, mainly used to treat bacterial infections. These drugs are functions either by killing or slow down the growth of bacteria. Amoxicillin, Doxycycline Azithromycin, and Penicillin are some examples of antibiotics.

  • What are Communicable diseases?

Communicable diseases are an infectious disease, which spread from a person to person and are caused by the pathogens. Tuberculosis, typhoid, scabies, plague, skin allergies are are some examples of communicable diseases.

  • Name few diseases caused by Protozoa.

Amoebic dysentery, Malaria, Sleeping sickness, Redness of eye and Ulcers are list of few diseases caused by protozoans.

  • How Can Disease Be Prevented?

Any disease, it can either be communicable disease and the non-communicable or allergies or any infections can be prevented if proper hygiene is maintained. Other preventive measures include:

  • Keep the surrounding clean and tidy.
  • Use of clean and boiled drinking water.
  • Always eat cleaned, washed and boiled food.
  • Get vaccinated or take medicines as prescribed
  • Frequently washing hands from germ free hand wash.

Stay tuned with BYJU’S to learn more about the types of human diseases and other related topics @ BYJU’S Biology.

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