Health and Disease


Health is the complete state of physical, mental and social well-being. However, we don’t just say that people are either healthy or unhealthy. The health of an individual falls on a spectrum, with some people being more or less healthy than others, in different ways.

There are many factors that affect the health of individuals, such as:

  • Getting enough exercise
  • Getting enough sleep
  • Eating a balanced diet
  • Having access to good healthcare
  • Not being overly stressed

So, the less we practice or have these healthy habits, the unhealthier we become.


Diseases can be grouped into communicable diseases and non-communicable diseases.

Communicable Disease

Communicable diseases are caused by pathogens (such as bacteria, fungi, viruses or parasites), which can be passed from one person (or animal) to another. We often call these infectious diseases.

Some examples of communicable diseases are:

  • The common cold
  • Chickenpox
  • Meningitis

Non-communicable Disease

Non-communicable diseases are not caused by pathogens and they cannot be spread between different people. They also tend to be long-lasting, with some that never go away.

Some examples of non-communicable diseases are:

  • Asthma
  • Coronary heart disease (CHD)
  • Diabetes
  • Most cancers

Interactions between Different Types of Disease

Sometimes, different types of diseases interact with each other. This can negatively impact an individual both physically and mentally, causing issues that might not seem related.

Below are some examples:

  • When a person has a weakened immune system, they are less able to defend themselves against communicable diseases. This often leads to them contracting infectious diseases, such as the common cold or influenza (flu).
  • When an individual has a mental illness, this can lead to physical problems, especially involving the immune system. The person is also more likely to make lifestyle decisions that further harm their health. These decisions can include neglecting sleep and hygiene, or avoiding social interactions.
  • Human papillomavirus (HPV) can cause cervical cancer in women by infecting cells of the cervix.
  • At times, the immune system can overreact while trying to combat a pathogen. This overreaction can harm the body’s tissues, triggering allergies such as rashes or asthma.

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