What is Disease?

In simple terms, we can define disease as a particular abnormal condition, or disturbance in the structure or the function of any organ or part of the body with specific symptoms and signs such as infection, inflammation, environmental factors, and genetic defect.

It may be caused due to the attack of pathogens (bacteria, viruses) and lack of a nutritious diet.

The study of diseases is known as pathology.

There are four main types of disease: 

1. Pathogenic diseases- These diseases are caused due to the attack of pathogens, such as bacteria and viruses.

Example- Pneumonia and Tuberculosis are caused by E.coli bacteria. AIDS, Measles, Smallpox are caused by viruses.

2. Deficiency diseases- These diseases are by a deficiency of a particular nutrient in the diet.

Example- Lack of vitamin C causes scurvy, lack of vitamin A causes night blindness, lack of vitamin D causes rickets.

3. Hereditary diseases- These diseases are passed on through generations via their genes.

Example- Sickle cell disease, Down syndrome.

4. Physiological diseases- These diseases are caused by the failure or malfunction of body parts or organs.

Example- Diabetes, Asthama, Glaucoma.


Simply Easy Learning

Updated on: 10-Oct-2022


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