The relationship between health and disease

In a nutshell

There are two main types of diseases: communicable and non-communicable. One disease can lead to other physical and mental health issues. Several factors can impact one's health.

Health and disease

Health is a state of physical and mental wellbeing, not simply being free from disease. However, diseases are often responsible for causing poor health. Diseases are disorders that can prevent parts of the body from functioning properly. There are two main groups of diseases: communicable and non-communicable.

Disease	Description	Examples
Communicable	They are caused by pathogens, including bacteria, viruses, parasites or fungi. They can be spread between people or between animals.	Malaria, measles and COVID-19.
Non-communicable	They are not transferred between people or animals.	Coronary heart disease, cancer and diabetes.

Complications and interactions

Diseases can often lead to other physical and mental health issues.

Examples

Viruses infect cells in the body and can potentially lead to various types of cancer (e.g. the human papillomavirus (HPV) can cause cervical cancer).
People who have problems with their immune system are more likely to suffer from communicable diseases, as they are less able to fight off pathogens.
Having a physical health problem can lead to mental health conditions, including depression and anxiety.
A pathogen may cause an immune system reaction which can lead to an allergic reaction. This can present as a skin rash or a worsening of asthma symptoms in some people.

Factors affecting health

There are other factors that can have a great impact on both physical and mental health. Some of these factors are explained below.

Factor	Explanation
Diet	Having a poor diet may result in the body being malnourished and lead to deficiencies in important nutrients.
Stress	Being under lots of stress can lead to poor health.
Life circumstances	One's life situations can affect how easily someone can access healthcare and other amenities.
Lifestyle	This includes drugs and alcohol and can have a negative impact on health.