Module 1 of 5
Define health holistically. Distinguish between wellness, illness, and disease. Understand social determinants of health.
This content is for educational purposes only. It does not constitute medical advice, diagnosis, or treatment. All health decisions — especially regarding pregnancy, child health, medications, and mental health — should be made in consultation with a qualified healthcare professional. If you or someone you know is experiencing a medical emergency, seek care immediately.
Grace is 34 years old. She lives in Kisumu, on the western shore of Lake Victoria. By most measures, she is healthy — she has no disease, takes no medication, and has not visited a clinic in years. But Grace wakes up tired every morning. Her family's water source is a shared tap two streets away that sometimes runs dry. Her youngest child missed three months of school last year because of repeated bouts of diarrhea. Her husband lost his informal market job when the rains flooded the stalls. Grace does not think of herself as having a health problem. But something is wrong.
This module is about understanding what health actually means — and why Grace's situation is a health story even before a doctor is involved.
Most people define health as 'not being sick.' If you have no fever, no pain, no visible disease — you are healthy. This is understandable. But it is incomplete, and that incompleteness has real consequences for how communities understand and respond to their own wellbeing.
In 1948, the World Health Organization offered a definition that remains the global standard: Health is a state of complete physical, mental, and social well-being — not merely the absence of disease or infirmity. Three words matter here: physical, mental, and social. All three together. Not one without the others.
Physical health is what most people think of first — the body's ability to function, fight infection, heal, and sustain energy. But mental health — emotional and psychological wellbeing — affects every aspect of physical health. A person experiencing chronic stress has elevated cortisol levels that suppress the immune system and raise blood pressure. A person experiencing depression may not eat, sleep, or seek care even when symptoms are serious. And social health — the quality of one's relationships, community ties, and sense of belonging — is now understood to be as powerful a predictor of health outcomes as diet or exercise.
Grace in Kisumu is not mentally ill or physically diseased. But her social health — eroded by economic instability, housing insecurity, and community stress — is shaping her physical wellbeing in ways that no single clinic visit will fix.
Social isolation increases the risk of premature death by 29% — comparable to smoking up to 15 cigarettes per day.
Source: Holt-Lunstad et al. (2015), published in Perspectives on Psychological Science; WHO Social Determinants of Health Commission
Why are some communities healthier than others? Why does a child born in Westlands, Nairobi have a dramatically different health trajectory than a child born in Mathare? The answer is not primarily genetic. It is structural.
The World Health Organization defines the social determinants of health as the conditions in which people are born, grow, live, work, and age — shaped by the distribution of money, power, and resources at global, national, and local levels. These determinants include:
Income and economic stability — Poverty limits access to nutritious food, clean water, safe housing, and healthcare. It also creates chronic stress that directly damages health.
Education — Higher education is consistently linked to better health literacy, higher income, and longer life expectancy. Children who complete secondary school are significantly more likely to vaccinate their own children.
Access to healthcare — Physical proximity to a clinic, cost of services, and cultural trust in health systems all determine whether people get care when they need it.
Neighborhood and built environment — Access to clean water, sanitation, safe roads, and green space directly affects disease burden. Inadequate WASH (Water, Sanitation, and Hygiene) alone causes an estimated 297,000 child deaths annually in sub-Saharan Africa.
Social and community context — Community cohesion, safety from violence, and freedom from discrimination all affect health. Communities that trust each other coordinate better during outbreaks, vaccinate at higher rates, and care for their sick more effectively.
Understanding social determinants matters for a practical reason: it tells you where health interventions actually need to happen. A community health worker who only treats symptoms at the point of illness is working downstream of the real problem. One who helps families access clean water, links children to school feeding programs, and connects unemployed adults to livelihood support is doing health work — even without a stethoscope.
In Nairobi's informal settlements — Korogocho, Viwandani, and others — population density, poor sanitation, and limited healthcare access created predictable health crises: high rates of diarrheal disease, respiratory infections, and preventable maternal and child deaths.
Tupange (a Swahili word meaning 'let us plan') was a family planning initiative that addressed health not through clinics alone but through community health workers embedded in the settlements themselves. CHWs conducted home visits, mapped social networks, identified women at risk during pregnancy, and connected households to sanitation resources. Within four years, contraceptive use increased by 24 percentage points in target settlements, and health-seeking behavior for maternal care improved significantly.
The lesson: health outcomes in Nairobi's settlements did not change because new clinics were built. They changed because trusted community members were equipped with knowledge and connected people to existing resources.
Three terms are often used interchangeably but mean different things — and the differences matter for how communities respond to health challenges.
Disease is a specific, diagnosable pathological condition — malaria, tuberculosis, hypertension, diabetes. Disease has identifiable causes, symptoms, and treatments. It is what clinics are primarily designed to address.
Illness is the subjective experience of feeling unwell. A person can have a disease without feeling ill (many people with hypertension feel fine until they have a stroke). A person can feel ill without having a diagnosable disease. Illness is what brings people to seek care — or, if stigmatized or too costly, what keeps them away.
Wellness is the active, ongoing pursuit of health across all three dimensions — physical, mental, and social. It is not a destination but a practice. You do not 'achieve' wellness the way you cure a disease. You maintain it daily through choices, relationships, and environments.
Community health workers operate across all three of these domains. They help prevent disease through education and vaccination support. They help people navigate illness by reducing stigma and supporting care-seeking. And they promote wellness by connecting communities to the conditions that make health possible.
Health is not static. It changes across the stages of life — and decisions made at one stage shape what is possible at another. This is called the life course approach to health, and it is central to how Kenya's Ministry of Health and global agencies like UNICEF and WHO plan interventions.
Pregnancy and infancy: The first 1,000 days of life — from conception to age two — represent the single most critical window for human development. Nutrition, infection prevention, and stimulation during this period have effects that last a lifetime.
Childhood: Vaccination, nutrition, education, and freedom from abuse and neglect all shape physical and cognitive development. School-age children who are hungry, sick, or afraid cannot learn.
Adolescence: Mental health challenges most often emerge during adolescence. Safe spaces, trusted adults, and access to accurate sexual and reproductive health information are critical.
Adulthood: Chronic disease risk accumulates. Lifestyle factors — diet, physical activity, tobacco, alcohol — compound over decades. Prevention is far less costly than treatment.
Older age: Social isolation becomes a major health risk. Community connection, economic security, and access to respectful elder care determine quality of life and longevity.
Approximately 45% of all deaths of children under 5 are linked to malnutrition — yet malnutrition is almost entirely preventable with adequate food, clean water, and healthcare access.
Source: UNICEF, WHO, World Bank — Joint Child Malnutrition Estimates (2023)
Draw or write a simple map of your community's health determinants.
On a piece of paper, write your community's name in the center. Around it, write answers to these questions: Where does water come from — is it reliable and clean? How far is the nearest clinic, and what does it cost to use? What is the main source of income? Are there schools within walking distance? Is the area safe? What happens when someone gets seriously ill — who do people call first?
Identify the two strongest and two weakest determinants.
Look at your map. Circle the two things your community does well. Underline the two biggest gaps. These gaps are where health problems are most likely to concentrate — and where community health work can have the most impact.
Write one sentence describing what 'wellness' would look like in your specific community.
Not a generic definition — a concrete, specific picture. 'Wellness in my community would mean every child under 5 has been vaccinated, every pregnant woman delivers at a facility, and no family chooses between food and clinic fees.' Keep this sentence. You will return to it at the end of this course.
Health is not the absence of disease — it is the presence of conditions that allow people to thrive. Understanding those conditions is the first job of anyone who wants to improve health in their community.
Want to go further? These free resources are the next step:
WHO Social Determinants of Health — The official WHO framework with evidence summaries and country case studies who.int/health-topics/social-determinants-of-health
Kenya Health Sector Strategic Plan (KHSSP) — Kenya's official national health framework — understand how the government thinks about health priorities health.go.ke
UNICEF — The First 1,000 Days — Plain-language overview of why early life health matters so much unicef.org/nutrition/index_first-1000-days.html
Answer this question before completing the module
List three factors in your daily environment — food, housing, relationships, or work — that you believe most affect your health right now. For each one, describe one small change you could make this month to improve it.
Score 2 out of 3 to complete this module
1. The World Health Organization defines health as more than just the absence of disease. Which of the following best captures that broader definition?
2. A family in a rural community has limited access to clean water, nutritious food is expensive, and the nearest health centre is far away. Which term best describes these underlying causes of poor health?
3. Amara notices that most people in her neighbourhood get sick at the same time each year during the rainy season. What is the most useful first step she could take to understand and address this pattern?