8A.2 - Health and life-expectancy inequalities

Basic needs and survival

Preventable illness becomes more dangerous when households lack safe water, sufficient food or timely care.

Infant mortality counts deaths before age one per 1,000 live births. The maternal mortality ratio counts maternal deaths related to pregnancy or its management per 100,000 live births. Their denominators differ, so their numerical values cannot be compared as if they were the same measure. Deaths very early in life reduce life expectancy sharply; reducing infant mortality can therefore raise it substantially.

Unsafe water and inadequate sanitation spread pathogens through contaminated drinking water and food. Diarrhoeal disease can cause dehydration, while undernutrition weakens resistance and delays recovery. Infection and undernutrition can reinforce each other: illness reduces nutrient absorption and ability to work, making food insecurity worse. Clean water, sanitation, vaccination and accessible primary care interrupt different links in this chain.

Maternal survival depends on nutrition, antenatal care, skilled attendance and rapid treatment of complications such as severe bleeding. A long journey, unaffordable transport or a clinic without supplies can turn a treatable emergency into a death. Poverty operates through these specific barriers, rather than acting as a medical cause by itself.

WHO estimates for 2023 place about 70% of global maternal deaths in sub-Saharan Africa. That is a share of deaths, not the region's maternal mortality ratio or the risk for every woman. The distribution reflects unequal services, poverty and conflict, with considerable differences between countries and communities. WHO maternal mortality factsheet, 2025.

Deprivation, lifestyles and care

High national income does not remove the social conditions that expose people to disease or delay treatment.

In wealthier countries, smoking, harmful alcohol use, poor diet and inactivity contribute to chronic illnesses such as cardiovascular disease. These behaviours are socially patterned. Low income can limit access to nutritious food, secure housing and recreation; stressful work and neighbourhood conditions can shape behaviour. Describing a lifestyle without its constraints risks blaming individuals while overlooking causes that policy can change.

Deprivation includes disadvantages in income, employment, housing, services and the living environment. Damp housing can worsen respiratory illness. Polluted neighbourhoods and insecure jobs increase exposure or stress. Illness can then reduce earnings, forming a feedback that deepens deprivation.

Medical care changes the chance that illness is prevented, diagnosed and treated. Availability concerns whether an appropriate service exists nearby; cost includes fees, travel and time away from work; effectiveness concerns whether treatment improves outcomes. Free care at the point of use does not remove waiting lists, inaccessible transport or language barriers. Conversely, expensive technology may add little if primary care cannot reach those at greatest risk.

Use the terms developing and developed as broad contexts, not two uniform medical worlds. Chronic and infectious diseases can coexist at any income level. The explanatory balance changes between places, and health inequalities remain within both groups.

Inequalities within countries

National averages conceal unequal experiences among neighbourhoods, income groups and ethnic populations.