Chapter 4. Health and Disease Determinants
Dr. Fantu Lombamo Untiso, Public Health Specialist Medical Doctor · St. Paul's Hospital Millennium Medical College
Why does a child in one kebele grow strong while a child in the next stays stunted? Doctors treat the illness; public health asks what made it likely. In this chapter you learn to look ‘upstream’ at the conditions that shape health, and to separate underlying causes from the final events.
Chapter 4 of 11 · Week 2 · 4 contact hours
Learning objectives for this chapter
- Define a determinant of health and distinguish determinants from risk factors and from direct and indirect contributing factors.
- Describe biological, socioeconomic, environmental, behavioural, health service and organisational determinants with examples.
- Use a framework (Lalonde, Dahlgren-Whitehead, WHO commission) to analyse the causes of a health problem.
- Explain the social gradient and the difference between equality and equity in health.
1. What is a determinant of health?
A determinant of health is any factor that influences the health of individuals or populations, positively or negatively. Determinants act at several levels and over the whole life course. Some are fixed (genes), some can be changed by a person (smoking), and many are outside individual control (income, clean water, laws).
The determinants of health and the determinants of disease are not the same thing. Smoking is a determinant of lung cancer; poverty and tobacco advertising are determinants of smoking. Public health looks for the ‘causes of the causes’ GBD 2023.
2. Categories of determinants
| Category | Examples | How public health acts |
|---|---|---|
| Biological / heredity | Age, sex, genetic risk (sickle cell disease, familial hypercholesterolaemia), ageing | Screening, genetic counselling, tailored care; cannot be ‘changed’, but impact can be reduced |
| Socioeconomic (social and economic) | Income, education, employment, housing, social support, gender, discrimination, conflict | Social protection, education, income policy, equity-focused programmes |
| Environmental (physical) | Water and sanitation, air quality (including indoor smoke from biomass fuel), food safety, climate, built environment, occupational hazards | Standards, regulation, infrastructure, climate adaptation |
| Behavioural (lifestyle) | Tobacco, alcohol, diet, physical activity, sexual behaviour, hygiene, health-seeking | Health education, taxes, laws, supportive environments |
| Health service | Access, quality and affordability of care; vaccination coverage; availability of medicines and skilled staff | Health system strengthening, UHC, quality improvement |
| Organisational / structural | How institutions are governed and managed: school and workplace policies, health policy and financing, governance, corruption, trade and commercial practices, health system management | Policy and governance reform, accountability, regulation of harmful industries |
3. Frameworks: seeing the layers
Lalonde (1974) divided health into four fields: human biology, environment, lifestyle and health care organisation. Dahlgren and Whitehead (1991) arranged determinants in layers, from the individual at the centre to broad social conditions at the edge. The WHO Commission on Social Determinants of Health (2008) separated structural determinants (income, education, gender, race, governance, which create a social position) from intermediary determinants (living conditions, behaviours, health system) and called for closing the gap in a generation.
Two ideas matter in the figure. First, factors in the outer layers change the options available in the inner layers: a poor family may want to cook with clean fuel but cannot afford it. Second, action at the outer layers (policy, economy) can reach everyone, whereas education at the centre reaches only those who can use it.
4. The social gradient
In almost every society, health improves with each step up the social ladder. This is the social gradient; it affects everyone and not just the poorest. Studies of British civil servants (Whitehall, led by Michael Marmot) showed that even among people with stable jobs, those in lower grades had much higher mortality. Gradients are found in Ethiopia too: children in the poorest households are more likely to be stunted and less likely to be fully vaccinated than those in the richest.
5. Determinants, risk factors and contributing factors
| Concept | Definition | Example (child undernutrition) |
|---|---|---|
| Determinant | A factor at any level that shapes the probability of health or disease; often distal (upstream) | Household poverty, low maternal education, gender inequality, food prices, armed conflict |
| Risk factor | A specific attribute or exposure that raises the probability of a disease | Low birth weight, no exclusive breastfeeding, diarrhoea, poor complementary feeding |
| Direct (proximate) cause | The factor that acts immediately on the body | Inadequate food intake and repeated infection |
| Indirect (underlying) contributing factor | Factors that act through the direct causes | Household food insecurity, poor water and sanitation, inadequate care and health services |
| Basic (root) cause | Social, economic and political structures | Poverty, governance, markets, climate, conflict |
This is the logic of the UNICEF framework for child undernutrition: immediate causes (diet, disease), underlying causes (food, care, health services and environment) and basic causes (resources, institutions, politics). The Mosley-Chen model of child survival makes the same point: social and economic factors act on child health through intermediate variables such as breastfeeding, sanitation and infection control.
6. Newer ideas
- Commercial determinants of health: the ways in which private industry shapes health, for example through marketing of tobacco, alcohol, breast-milk substitutes and ultra-processed foods. In 2025, the World Health Assembly extended the Code on breast-milk substitutes to cover digital marketing WHA78 2025.
- Climate and environment: air pollution, heat and extreme weather. The 2025 Assembly set a target to halve the health impact of air pollution by 2040, and WHO reported that nearly 60 percent of new emergencies in the previous year were climate-related WHA78 2025. The GBD 2023 study found that deaths from environmental heat and cold rose by about 6 percent a year from 2013 to 2023 GBD 2023.
- Digital determinants: access to phones, data and information, which can improve or worsen inequality in access to health information and services.
- Conflict and displacement: war destroys facilities, interrupts vaccination and drives malnutrition. In Ethiopia, drought, conflict and displacement together fuel outbreaks and malnutrition UNICEF SitRep 2026.
7. Equality and equity
Equality means giving everyone the same resource. Equity means giving each group what it needs to reach the same opportunity for health, which usually means more for those who have less. Health inequalities are measurable differences between groups; inequities are those that are avoidable and unfair. The Sustainable Development Goals’ promise to ‘leave no one behind’ requires that data be broken down by income, sex, residence, age and disability.
Part of the course: Fundamentals of Public Health
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For licensed professionals and students. Educational information only: always follow current national guidelines (EFDA, Ministry of Health), the product label and your facility’s procedures.