WHO’s latest global data show a world increasingly dominated by chronic diseases, but Nigeria continues to face a double burden of infectious and non-communicable diseases.

The diseases killing people around the world are increasingly chronic ones, with heart disease, stroke, diabetes and other non-communicable diseases dominating the latest global mortality figures. But Nigeria’s health burden tells a more complicated story. While cardiovascular diseases are becoming increasingly important, infectious diseases, maternal conditions and illnesses affecting newborns still account for a substantial share of deaths in the country.

The contrast is highlighted by the World Health Organisation’s latest Global Health Estimates, which found that eight of the world’s 10 leading causes of death in 2023 were non-communicable diseases.

The 10 leading causes collectively accounted for about 33 million of the 61 million deaths recorded globally that year. Ischaemic heart disease was responsible for approximately 9.5 million deaths, followed by stroke with 6.8 million, while chronic obstructive pulmonary disease caused another 3.6 million deaths. Diabetes, cancer, hypertensive heart disease and kidney disease also featured among the world’s biggest killers.

What Is Killing the World?

Ischaemic heart disease remained the world’s leading cause of death in 2023, accounting for about 16 per cent of all deaths globally. Stroke ranked second, followed by chronic obstructive pulmonary disease and lower respiratory infections. Alzheimer’s disease and other dementias ranked fifth, while diabetes was sixth, followed by cancers of the trachea, bronchus and lung, hypertensive heart disease, kidney diseases and diarrhoeal diseases. Together, the figures show how much the global mortality picture has shifted towards conditions associated with ageing, cardiovascular risk factors and other chronic health problems.

The trend is particularly significant because non-communicable diseases are no longer simply a problem of wealthy countries. WHO says NCDs accounted for 74 per cent of all deaths globally in 2023, compared with 58 per cent in 2000. In lower-middle-income countries, including Nigeria, the transition is less advanced but is already visible. Five of the 10 leading causes of death in this income group in 2023 were NCDs, while communicable, maternal, neonatal and nutritional conditions continued to occupy a significant part of the ranking.

Where Nigeria Differs

Nigeria’s latest WHO cause-of-death profile presents a markedly different picture. The organisation’s Nigeria country data, based on 2021 estimates, put lower respiratory infections at the top, with an estimated mortality rate of 89.7 deaths per 100,000 people. Malaria followed at 84.2 deaths per 100,000, while diarrhoeal diseases recorded 69.9 and tuberculosis 57.7. Ischaemic heart disease ranked fifth at 33.9 deaths per 100,000, followed by birth asphyxia and birth trauma at 33.7 and stroke at 33.3. Preterm birth complications, maternal conditions and HIV/AIDS completed Nigeria’s estimated top 10 causes of death.

The difference is significant. While ischaemic heart disease and stroke sit at the top of the global ranking, Nigeria’s leading estimated causes still include malaria, tuberculosis, diarrhoeal diseases, maternal conditions and complications affecting newborns. This does not mean chronic diseases are insignificant in Nigeria. Rather, it shows that the country is dealing with several stages of the health transition at the same time: diseases that have become less dominant in many parts of the world remain major killers, even as cardiovascular disease, diabetes, kidney disease and other chronic conditions increasingly place pressure on the health system.

Infectious Diseases Still Matter

Malaria remains one of the clearest examples of the difference between Nigeria’s health burden and the global picture. WHO’s latest malaria estimates show that the African Region accounted for about 95 per cent of global malaria cases and deaths in 2024, with Nigeria alone accounting for approximately 31.9 per cent of malaria deaths in the region. The disease therefore remains a major public-health challenge in Nigeria at a time when the global mortality conversation is increasingly focused on cardiovascular disease, cancer, dementia and diabetes.

The WHO’s Nigeria estimates reinforce the scale of that burden. Communicable, maternal, perinatal and nutritional conditions accounted for an estimated 63.7 per cent of deaths in 2021, compared with 27.7 per cent from non-communicable diseases and 7.8 per cent from injuries.

The figures underline why Nigeria cannot simply adopt the global narrative that chronic diseases have replaced infectious diseases as the country’s principal health threat. For millions of Nigerians, access to effective prevention and treatment for malaria, tuberculosis, respiratory infections and other communicable diseases remains a matter of life and death.

But Heart Disease and Stroke Are Rising

At the same time, the prominence of ischaemic heart disease and stroke in Nigeria’s mortality estimates points to another challenge that cannot be ignored. Cardiovascular disease is already among the country’s leading estimated causes of death, with heart disease ranked fifth and stroke seventh in the WHO’s 2021 profile. Research published by the Lancet Nigeria Commission has similarly identified cardiovascular disease as an increasingly important contributor to mortality, with ischaemic heart disease and stroke among the country’s major causes of death.

The global trend suggests that this burden is likely to become increasingly important as Nigeria’s population grows and ages. WHO’s latest data show that deaths from ischaemic heart disease, stroke and chronic obstructive pulmonary disease increased substantially across lower-middle-income countries between 2000 and 2023, while diabetes also climbed sharply up the mortality ranking. Nigeria therefore faces the difficult task of managing chronic diseases at the same time as it continues to battle infectious diseases that remain major causes of preventable death.

Maternal and Child Health Remain Major Concerns

Nigeria’s mortality picture also includes causes that receive far less attention in global rankings but remain critical within the country. Maternal conditions, birth asphyxia and birth trauma and complications associated with preterm birth all appeared among the country’s 10 leading estimated causes of death in the WHO’s 2021 data. This highlights another important difference between Nigeria and countries where mortality is increasingly concentrated among older populations living with chronic diseases.

Maternal mortality remains particularly serious. WHO’s latest country data put Nigeria’s maternal mortality ratio at approximately 1,000 deaths per 100,000 live births in 2023, although the estimate carries a wide uncertainty range. The persistence of maternal and newborn deaths alongside malaria, tuberculosis and respiratory infections means Nigeria’s health priorities cannot be built around non-communicable diseases alone. The country must continue addressing access to antenatal care, skilled birth attendance, emergency obstetric services and newborn care while also preparing for the increasing burden of chronic illness.

Nigeria’s Other Major Health Challenge: Data

There is, however, a major limitation to any attempt to produce a precise Nigeria-versus-world comparison: Nigeria does not yet have a sufficiently complete national system for recording deaths and their causes. WHO states that death-registration data for Nigeria are unavailable or unusable for cause-of-death analysis because of data-quality problems. As a result, the organisation relies on statistical estimates generated from multiple sources to produce Nigeria’s cause-of-death profile.

That limitation matters because WHO’s latest global estimates cover 2023, while the Nigeria-specific leading-cause table currently displayed by WHO is based on 2021 estimates. The two datasets therefore should not be presented as though they were an exact 2023 head-to-head ranking. The difference does not make the comparison useless, but it does mean the figures should be treated as an indication of the country’s broader mortality pattern rather than a precise snapshot of what killed Nigerians in the same year as the global ranking.

A Country Facing Two Health Battles

What the data ultimately show is not that Nigeria is following or resisting the global shift towards chronic diseases, but that the country is experiencing several health challenges simultaneously. Heart disease and stroke are already significant causes of death, and diabetes and other non-communicable diseases are likely to become increasingly important as the population changes. Yet malaria, respiratory infections, tuberculosis, diarrhoeal diseases, maternal conditions and complications affecting newborns continue to claim lives at a scale that makes infectious and maternal health impossible to treat as yesterday’s problems.

For Nigeria, therefore, the question is not whether the country should focus on infectious diseases or non-communicable diseases. It is how the health system can respond to both. Preventing malaria and tuberculosis deaths, improving maternal and newborn care, expanding access to diagnosis and treatment for hypertension and diabetes, and strengthening cardiovascular care all require resources, reliable data and a health system capable of detecting the country’s changing needs.

The WHO’s global figures offer a warning about where the world’s health burden is heading, but Nigeria’s own numbers show why the country cannot afford to look only at the global picture. The world’s biggest killers may increasingly be chronic diseases, but Nigeria is still fighting yesterday’s killers while preparing for tomorrow’s.