8.5 Non-Infectious Diseases

Introduction

Not all diseases are caused by pathogens. Many diseases are caused by genetic factors, lifestyle choices, environmental factors, or a combination of these. These are called non-infectious diseases. They cannot spread from person to person. This topic explains the types of non-infectious diseases.

Definition

Non-infectious diseases are diseases that are not caused by pathogens and cannot spread from person to person.

Main Idea

Non-infectious diseases are not caused by pathogens and cannot spread from person to person.

These include:

• Physiological diseases (e.g., type 2 diabetes, cancer)
• Genetic disorders (e.g., sickle cell anaemia, colour blindness)
• Autoimmune diseases (e.g., type 1 diabetes, rheumatoid arthritis)
• Nutritional deficiency diseases (e.g., scurvy, rickets)
• Environmental diseases (e.g., lung cancer from smoking, skin cancer from UV rays)
• Degenerative diseases (e.g., osteoarthritis, Alzheimer's disease)
• Psychological disorders (e.g., anxiety disorders, depression)

Core Concept

Types of Non-Infectious Diseases

Detailed Explanation

1. What are Non-Infectious Diseases?

Non-infectious diseases are not caused by pathogens and cannot spread from person to person.

Simple explanation: Non-infectious diseases are diseases that are not contagious. You cannot catch them from someone else.

Why this is important:

• Non-infectious diseases are a major cause of death worldwide.
• They often require long-term management.
• Many can be prevented through lifestyle changes.

2. Types of Non-Infectious Diseases

(a) Physiological diseases:

• Diseases caused by physiological dysfunction.
• Examples: Type 2 diabetes, cancer.

(b) Genetic disorders:

• Diseases caused by genetic mutations.
• Examples: Sickle cell anaemia, colour blindness.

(c) Autoimmune diseases:

• Diseases where the immune system attacks the body's own tissues.
• Examples: Type 1 diabetes, rheumatoid arthritis.

(d) Nutritional deficiency diseases:

• Diseases caused by lack of essential nutrients.
• Examples: Scurvy (vitamin C deficiency), rickets (vitamin D deficiency).

(e) Environmental diseases:

• Diseases caused by environmental factors.
• Examples: Lung cancer from smoking, skin cancer from UV rays.

(f) Degenerative diseases:

• Diseases caused by degeneration of tissues or organs.
• Examples: Osteoarthritis, Alzheimer's disease.

(g) Psychological disorders:

• Disorders of mental health.
• Examples: Anxiety disorders, depression.

Simple explanation:

• Physiological — body functions go wrong (diabetes, cancer).
• Genetic — inherited from parents (sickle cell anaemia).
• Autoimmune — immune system attacks the body (type 1 diabetes).
• Nutritional deficiency — lack of nutrients (scurvy, rickets).
• Environmental — caused by pollution, smoking, UV rays.
• Degenerative — tissues break down over time (osteoarthritis).
• Psychological — mental health issues (depression).

Summary Table

Intermediate Level

Non-infectious diseases are not caused by pathogens and cannot spread from person to person.

Key points:

• Non-infectious diseases are not contagious.
• They are caused by genetics, lifestyle, environment, or a combination of factors.
• Many can be prevented through lifestyle changes.
• They often require long-term management.

Important Points

• - Non-infectious diseases are not caused by pathogens and cannot spread from person to person.
• - These include:
• - Physiological diseases (e.g., type 2 diabetes, cancer)
• - Genetic disorders (e.g., sickle cell anaemia, colour blindness)
• - Autoimmune diseases (e.g., type 1 diabetes, rheumatoid arthritis)
• - Nutritional deficiency diseases (e.g., scurvy, rickets)
• - Environmental diseases (e.g., lung cancer from smoking, skin cancer from UV rays)
• - Degenerative diseases (e.g., osteoarthritis, Alzheimer's disease)
• - Psychological disorders (e.g., anxiety disorders, depression)

Remember

• - Non-infectious diseases = not caused by pathogens, cannot spread
• - Types = physiological, genetic, autoimmune, nutritional deficiency, environmental, degenerative, psychological
• - Physiological = type 2 diabetes, cancer
• - Genetic = sickle cell anaemia, colour blindness
• - Autoimmune = type 1 diabetes, rheumatoid arthritis
• - Nutritional deficiency = scurvy, rickets
• - Environmental = lung cancer from smoking, skin cancer from UV rays
• - Degenerative = osteoarthritis, Alzheimer's disease
• - Psychological = anxiety disorders, depression

Common Mistakes

• 1. Confusing non-infectious and infectious diseases.
• - Non-infectious = not caused by pathogens, cannot spread.
• - Infectious = caused by pathogens, can spread.
• 2. Thinking all non-infectious diseases are genetic.
• - Non-infectious diseases can be physiological, autoimmune, nutritional, environmental, degenerative, or psychological.
• 3. Mixing up autoimmune and genetic diseases.
• - Autoimmune = immune system attacks the body.
• - Genetic = caused by mutations in genes.
• 4. Forgetting that nutritional deficiencies can cause diseases.
• - Scurvy (vitamin C), rickets (vitamin D), anaemia (iron).
• 5. Believing non-infectious diseases cannot be prevented.
• - Many can be prevented through lifestyle changes.
• 6. Confusing degenerative and physiological diseases.
• - Degenerative = tissues break down over time.
• - Physiological = body functions go wrong.
• 7. Thinking psychological disorders are not real diseases.
• - Psychological disorders are real medical conditions.

Quick Revision

60-Second Revision

• Non-infectious diseases = not caused by pathogens, cannot spread
• Types = physiological, genetic, autoimmune, nutritional deficiency, environmental, degenerative, psychological
• Physiological = type 2 diabetes, cancer
• Genetic = sickle cell anaemia, colour blindness
• Autoimmune = type 1 diabetes, rheumatoid arthritis
• Nutritional deficiency = scurvy, rickets
• Environmental = lung cancer from smoking, skin cancer from UV rays
• Degenerative = osteoarthritis, Alzheimer's disease
• Psychological = anxiety disorders, depression
• Warning: Do not confuse non-infectious (cannot spread) with infectious (can spread) diseases.