Biological, Environmental, Sociocultural Factors

1. Biological Factors

Biological factors relate to the structure and function of the body and can be influenced by genetics, lifestyle, and environmental exposure.

1.1 Body Weight

• High body weight (overweight/obesity) increases the risk of:

  • Coronary heart disease

  • Type 2 diabetes

  • Some cancers

  • Joint and mobility issues (knee/hip problems)

  • Sleep apnoea

  • Social exclusion and mental health issues

• Causes of obesity:

  • Energy imbalance (calories consumed > calories burned)

  • Shift towards energy-dense diets

  • Reduced physical activity levels

• Measurement indicators:

  • BMI (Body Mass Index):

    • Overweight = 25–29.9

    • Obese = 30+

  • Waist circumference:

    • Risk for women: >89 cm

    • Risk for men: >102 cm

• Trends:

  • In Australia, adult obesity rates increased from 56.3% in 1995 to 63.4% in 2014-15.

  • Children (5-17 years old) overweight/obesity rate in 2014-15: 25.8%.

1.2 Blood Pressure (Hypertension)

• Normal BP: 120/80 mmHg

• Hypertension (high blood pressure):

  • Increases risk of cardiovascular diseases (heart attack, stroke).

  • Causes:

    • Stress

    • Smoking

    • Excess alcohol

    • Poor diet (high sodium intake)

    • Genetic predisposition

1.3 Blood Cholesterol

• Types:

  • LDL (low-density lipoprotein) – "Bad cholesterol"

    • Accumulates on artery walls, increasing risk of heart disease.

  • HDL (high-density lipoprotein) – "Good cholesterol"

    • Removes excess cholesterol from blood vessels.

• High LDL levels lead to atherosclerosis (narrowed arteries, restricted blood flow).

• Causes:

  • High intake of saturated/trans fats (from animal products, processed foods).

  • Lack of exercise.

1.4 Glucose Regulation (Diabetes Risk)

• Insulin resistance (impaired glucose regulation):

  • Cells don’t respond properly to insulin, leading to high blood sugar.

  • Risk factors:

    • Genetics

    • Smoking

    • Overweight (especially abdominal fat)

  • Health risks:

    • Type 2 diabetes

    • Cardiovascular disease

    • Kidney disease

    • Premature death

1.5 Birth Weight

• Low birth weight (<2.5 kg):

  • Underdeveloped immune system → higher infection risk.

  • Increased risk of premature death.

  • Higher chance of speech, learning disabilities.

  • Long-term risks:

    • High blood pressure

    • Type 2 diabetes

    • Cardiovascular disease

• Causes:

  • Maternal malnutrition, smoking, alcohol use, infections.

1.6 Genetics

• Genetic inheritance affects:

  • Disease predisposition (e.g., cancer, heart disease).

  • Body type, hormone production.

  • Mental health traits.

• Genetic mutations can lead to conditions like:

  • Down syndrome

  • Some cancers

• Genetic predisposition means higher risk but not certainty of disease development.

1.7 Hormones

• Oestrogen (women):

  • Regulates menstrual cycle.

  • Protects bones (low levels post-menopause → osteoporosis risk).

  • May reduce heart disease risk.

• Testosterone (men):

  • Linked to higher risk-taking behavior.

  • Declines after age 40 → can lead to fatigue, depression.

2. Sociocultural Factors

Sociocultural factors relate to social and economic conditions that influence health.

2.1 Socioeconomic Status (SES)

• Higher SES → Better health outcomes.

• Lower SES risks:

  • Less likely to follow health advice.

  • Higher smoking rates.

  • Poor nutrition → obesity, diabetes.

  • Overcrowded housing → infections.

2.2 Unemployment

• Causes financial stress, leading to:

  • Higher suicide rates.

  • Increased lung cancer (often due to smoking).

  • Higher cardiovascular disease risk.

2.3 Social Exclusion

• Definition: Being cut off from participation in society.

• Causes:

  • Poverty, disability, mental illness.

  • Family breakdown, homelessness.

• Health impacts:

  • Mental illness.

  • Increased disease risk due to poor healthcare access.

2.4 Social Isolation

• Definition: Lack of regular social contact.

• Health effects:

  • Higher rates of mental illness.

  • Increased premature death risk.

  • Lower life expectancy.

2.5 Cultural Influences

• Gender roles:

  • Men less likely to seek medical help.

  • Women more likely to access healthcare.

• Food beliefs:

  • Certain diets increase/decrease obesity risk.

• Attitudes towards health:

  • Traditional medicine vs. modern healthcare use.

2.6 Food Security

• Definition: Having reliable access to safe, nutritious food.

• Lack of food security:

  • Leads to malnutrition or obesity (cheap processed foods).

  • Increases diabetes, cardiovascular disease risk.

2.7 Early Life Experiences

• Prenatal factors (maternal health, nutrition, substance use) affect lifelong health.

• Childhood neglect/abuse → Brain development issues, higher risk of chronic disease.

2.8 Access to Healthcare

• Barriers:

  • Geographic distance.

  • Cultural beliefs.

  • Financial constraints.

• Health impacts:

  • Increased mortality and disease rates.

3. Environmental Factors

Environmental factors refer to physical surroundings that impact health.

3.1 Housing

• Poor housing conditions → Higher risks of:

  • Injury.

  • Mental health issues.

  • Respiratory diseases (e.g., asthma from mold).

3.2 Work Environment

• Risks include:

  • UV exposure → skin cancer.

  • Hazardous substances → lung disease.

  • Dangerous working conditions → accidents/injuries.

3.3 Urban Design & Infrastructure

• Transport access:

  • Impacts employment, healthcare, and food access.

  • Less active transport (walking, cycling) → obesity, diabetes risk.

3.4 Climate & Climate Change

• Australia’s climate risks:

  • Extreme temperatures (heatwaves, cold).

  • Natural disasters (bushfires, floods, droughts).

• Health effects:

  • Increased respiratory conditions.

  • Higher mental health stress due to natural disasters.