Social Determinants of Health: Complete Doctor's Notes
Health is not produced only inside a hospital. A person's health is shaped by biology, behaviour, family, culture, income, education, housing, work, environment, politics and the health system. These notes provide a detailed, clinically useful explanation of the social determinants of health (SDOH) for medical students, doctors and other health professionals.
After studying this topic, the learner should be able to define health and its determinants; explain the social gradient, health inequalities and health inequities; describe the Dahlgren–Whitehead model; classify structural and intermediary determinants; connect each determinant to disease pathways; take a socially informed history; and plan individual, community and policy-level responses.
1. The concept of health
The World Health Organization defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. In practice, health is multidimensional. It includes physical functioning, emotional and mental well-being, social relationships, ability to work or learn, ability to adapt to change, and the capacity to participate in family and community life.
Health can therefore be understood at three related levels:
- Individual health: the condition and functioning of one person.
- Population health: the health outcomes of a defined population and how those outcomes are distributed.
- Health equity: the removal of unfair and avoidable differences between groups.
2. What are social determinants of health?
Social determinants of health are the conditions in which people are born, grow, learn, work, live and age, together with the wider economic, social, cultural, environmental and political forces that shape those conditions. They include access to power, money, education, food, housing, transport, information and health services.
They are called “social” because they are largely created or modified by families, communities, institutions, markets, governments and social relationships. They are called “determinants” because they influence exposure to risks, vulnerability, health behaviours, ability to obtain care and the consequences of illness.
SDOH do not mean that social factors replace biology. Disease results from interaction between biological susceptibility, exposure, behaviour, environment and access to effective care. A socially informed doctor asks what happened medically and what circumstances made that illness more likely, more severe or more difficult to treat.
3. Why the determinants of health are important
- They explain why people with the same diagnosis may have different outcomes.
- They help clinicians identify causes and risks before complications occur.
- They guide prevention, health promotion and community diagnosis.
- They reveal why some patients repeatedly return with the same problem.
- They help health systems target resources where avoidable risk is greatest.
- They shift practice from blaming individuals to addressing modifiable causes.
Social conditions can influence exposure, susceptibility, disease recognition, health-seeking behaviour, treatment adherence, recovery, disability and survival. They may operate before birth, accumulate across life and pass through generations.
4. Dahlgren–Whitehead model: the “rainbow” of determinants
The Dahlgren–Whitehead model presents determinants as layers around the individual:
| Layer | Main elements | Clinical meaning |
|---|---|---|
| Individual factors | Age, sex, genetic inheritance and constitutional factors | Influence vulnerability, development, reproductive health and disease risk. |
| Individual lifestyle | Diet, activity, tobacco, alcohol, sleep, coping and sexual behaviour | Behaviours affect risk, but choices are constrained by social circumstances. |
| Social and community networks | Family, friends, peers, faith groups, community organisations and participation | Provide emotional, practical and informational support or may create pressure and stigma. |
| Living and working conditions | Housing, education, employment, workplace, water, sanitation, food, transport and health services | Shape daily exposure, access and the ability to protect health. |
| General socioeconomic, cultural and environmental conditions | Government, policy, economy, culture, social norms, environment and distribution of resources | Set the rules and opportunities that produce social position and health inequity. |
5. Structural determinants
Structural determinants create the social hierarchy in which people live. They include governance, laws, public policy, economic systems, social protection, taxation, education policy, labour markets, gender relations, racism, disability discrimination, conflict and commercial influence.
5.1 Socioeconomic position
Income, wealth, education and occupation influence food, housing, transport, safety, social networks, health literacy and the ability to pay for care. Poverty may cause illness directly through deprivation and indirectly through stress, unsafe work and delayed treatment. Wealth can protect health by providing choices and buffers during illness.
5.2 Political and policy environment
Government decisions affect health through health financing, public education, water systems, roads, housing regulation, food safety, tobacco and alcohol control, employment protection, social protection, refugee policy and emergency preparedness. A policy can create health or harm even when it is not labelled a health policy.
5.3 Gender, discrimination and social exclusion
Gender norms influence autonomy, exposure to violence, nutrition, workload, reproductive decisions and access to money. Discrimination based on ethnicity, disability, HIV status, mental illness, age, religion, sexuality or poverty may reduce trust and delay care. Doctors should recognise discrimination as a health risk, not as a patient defect.
6. Living and working conditions
6.1 Housing and physical environment
Overcrowding, poor ventilation and indoor air pollution increase respiratory infections and chronic lung disease. Unsafe structures increase injuries. Dampness and mould can worsen asthma. Insecurity and homelessness increase stress and make storage of medicines and regular follow-up difficult.
6.2 Water, sanitation and hygiene
Unsafe water, inadequate sanitation and poor hand hygiene contribute to diarrhoeal diseases, helminthic infections, cholera, typhoid and other outbreaks. Doctors should ask about water source, storage, latrine access, handwashing facilities and household crowding when evaluating recurrent gastrointestinal or infectious illness.
6.3 Food and agriculture
Food insecurity can cause undernutrition, anaemia, poor immunity, poor fetal growth and impaired learning. Cheap energy-dense foods can contribute to obesity, hypertension and diabetes. Agricultural work may involve pesticides, injuries, zoonoses, heat exposure and musculoskeletal strain. Food safety includes production, storage, preparation and distribution.
6.4 Employment and unemployment
Work can provide income, purpose and social connection, but may also expose people to dust, chemicals, noise, radiation, infection, heat, repetitive strain and injury. Unemployment may cause poverty, anxiety, depression, loss of routine and inability to pay for care. Ask about occupation, hazards, protective equipment, working hours and income insecurity.
6.5 Education and health literacy
Education improves employment opportunity, problem-solving, communication and the ability to understand health information. Low health literacy may result in incorrect medicine use, late recognition of danger signs and difficulty navigating referrals. Use simple language and ask the patient to explain the plan in their own words.
7. Health-care access as a determinant
Health services influence outcomes through more than the presence of a building. Important dimensions include:
- Availability: the service, staff, medicines, equipment and blood products exist.
- Accessibility: the patient can physically reach the service.
- Affordability: direct and indirect costs are manageable.
- Acceptability: care respects culture, beliefs, privacy and dignity.
- Quality and safety: care is evidence-based, timely and competent.
- Continuity: records, referrals, follow-up and chronic care are connected.
- Communication: patients receive information they can understand.
A patient may have a theoretically free service but still be unable to use it because of transport cost, long queues, lost wages, language barriers, stigma, disability access or fear of disrespect.
8. Social and community networks
Family and community support can provide money, transport, childcare, food, reminders, emotional reassurance and practical help. Social isolation can worsen depression, anxiety, frailty and treatment interruption. However, networks may also spread misinformation, reinforce stigma, delay referral or restrict a person's autonomy. Assess both protective and harmful effects.
Community participation and trust can improve immunisation, health education, epidemic control and uptake of preventive services. Doctors should work with community leaders and health workers without assuming that all community beliefs are either correct or harmful.
9. Individual and lifestyle factors
Age affects development, cumulative exposure, chronic disease and frailty. Sex-related biology and gendered social roles may produce different risks. Genetic inheritance and constitutional factors influence susceptibility but do not determine every outcome. Early brain development, nutrition, stress and exposure to violence can affect lifelong health.
Lifestyle factors include diet, activity, tobacco, alcohol, other substances, sleep, coping with stress and sexual behaviour. Effective counselling should identify the person's goals, barriers and resources. Advice is more useful when it is realistic, specific and linked to the patient's living conditions.
10. Life-course and intergenerational effects
Social disadvantage may begin before conception and continue through pregnancy, infancy, school, employment and old age. Maternal malnutrition, infection, stress and poor antenatal access may affect fetal growth. Childhood adversity may alter education, mental health, coping and later disease risk. Adult poverty may affect the next generation through nutrition, housing and education.
This is why prevention must include early childhood support, maternal health, safe schools, protection from violence, decent work, healthy ageing and social protection—not only treatment after disease appears.
11. Pathways from determinants to disease
| Pathway | Example |
|---|---|
| Material deprivation | Low income leads to food insecurity, anaemia and delayed treatment. |
| Hazard exposure | Dust, smoke or pesticides cause respiratory, neurological or occupational disease. |
| Psychosocial stress | Chronic insecurity activates stress pathways and worsens sleep, hypertension and mental health. |
| Behavioural adaptation | Smoking, harmful alcohol use or poor diet may become coping strategies. |
| Reduced access | Distance, cost or stigma delays diagnosis and increases complications. |
| Health-system failure | Stock-outs, poor referral or disrespectful care reduce trust and continuity. |
12. A socially informed medical history
Alongside the presenting complaint, ask relevant questions about housing, food, water, transport, work, education, income stress, social support, safety, violence, discrimination, substance use, health literacy and access to medicines. Explain why you are asking and maintain confidentiality.
Useful questions include: “Who helps you at home?” “How did you travel here?” “Have you ever missed medicines because of cost or distance?” “Is there enough food and safe water at home?” “What work do you do?” “What makes it difficult to follow the plan?” and “What would make this treatment easier for you?”
13. Role of doctors and clinicians
- Recognise: identify social causes and barriers during history and examination.
- Respond: adapt treatment to the patient's resources, language, culture and ability.
- Refer: connect the patient with social work, community health workers, mental-health services, protection services and relevant specialists.
- Advocate: report unsafe systems, support equitable care and contribute to policy and community action.
- Prevent: use screening, counselling, vaccination, early intervention and health promotion.
- Document: record relevant determinants respectfully and avoid blame.
- Evaluate: check whether the plan worked and revise it when barriers remain.
14. Levels of action
- Individual level: diagnosis, counselling, treatment, prevention and referral.
- Family and community level: outreach, health education, support groups, sanitation and community participation.
- Organisational level: respectful services, accessible clinic hours, reliable supplies and effective referral.
- Policy level: universal health coverage, social protection, safe housing, education, labour protection and regulation of harmful commercial products.
15. Clinical and public-health examples
Assess water source, sanitation, handwashing, food storage, household crowding and access to oral rehydration—not only the immediate pathogen.
Ask about food affordability, medicine stock-outs, work schedule, transport, health literacy, depression and family support.
Explore distance, cost, partner support, previous disrespect, cultural beliefs, workload, pregnancy recognition and availability of services.
Take an occupational history, identify exposure, assess protective equipment and advise on prevention, reporting and referral.
16. Common errors in examination answers and practice
- Listing poverty only and ignoring education, housing, culture, environment and health services.
- Describing lifestyle as personal choice without explaining social constraints.
- Confusing a determinant with a disease outcome.
- Assuming that a free service is automatically accessible.
- Blaming a patient for non-adherence without asking about cost, side effects or understanding.
- Using stereotypes instead of assessing the individual.
- Giving a referral without checking whether the patient can realistically reach it.
17. Summary for doctors
- Health is multidimensional and includes physical, mental and social well-being.
- SDOH are the conditions and systems shaping daily life and health opportunity.
- The rainbow model moves from individual factors to lifestyle, social networks, living and working conditions, and broad socioeconomic, cultural and environmental conditions.
- Structural determinants shape social position; intermediary determinants create daily exposures and vulnerability.
- Health inequities are unfair and avoidable differences, not simply any difference.
- Doctors should ask socially relevant questions, adapt care, coordinate referrals and advocate for healthier systems.
- Prevention requires action before disease appears and at individual, community, organisational and policy levels.
18. References and further reading
- World Health Organization. Social determinants of health.
- World Health Organization. Social determinants of health: fact sheet, 2025.
- Centers for Disease Control and Prevention. Why addressing social determinants of health is important.
- World Health Organization. Health promotion.
- World Health Organization. Ottawa Charter for Health Promotion.
- WHO Regional Office for Africa. Social and economic determinants of health.
- World Health Organization. World report on social determinants of health equity, 2025.
Educational note: This article supports study and clinical reasoning. It does not replace current Ministry of Health guidance, facility protocols or professional judgement.
