Health and non-communicable disease

Health is the state of physical and mental well-being.

It is influenced by:

• Disease (both communicable and non-communicable).

• Factors such as diet, stress, and life situations.

Types of disease

Communicable diseases are passed from one organism to another (e.g., through pathogens like bacteria or viruses). See Topic 3 for more information and examples.

Non-communicable diseases cannot be passed between organisms.

Examples include:

• Heart disease: Often caused by a poor diet.

• Liver disease: Linked to excessive alcohol consumption.

• Cancer: Caused by multiple factors, including:

  • Genetic mutations.

  • Poor diet.

  • Exposure to carcinogens (e.g., chemicals in cigarette smoke).

Non-communicable diseases usually result from multiple risk factors. The more risk factors present, the greater the likelihood of developing the disease.

Disease interaction

Diseases can interact with each other, leading to more severe health issues:

• Viruses living in cells can trigger cancers.

• Immune reactions caused by a pathogen can lead to allergies (e.g., asthma, skin rashes).

• Severe physical illnesses can result in mental health issues like depression.

Additional maths skills