Leading cause of death and disability worldwide

Heart disease remains the number 1 killer; diabetes and dementia enter the top 10

Heart disease has remained the leading cause of death at the global level for the last 20 years. However, it is now killing more people than ever before. The number of deaths from heart disease increased by more than 2 million since 2000, to nearly 9 million in 2019. Heart disease now represents 16% of total deaths from all causes. More than half of the 2 million additional deaths were in the WHO Western Pacific region. Conversely, the European region has seen a relative decline in heart disease, with deaths falling by 15% [1].

Deaths from diabetes increased by 70% globally between 2000 and 2019, with an 80% rise in deaths among males. In the Eastern Mediterranean, deaths from diabetes have more than doubled and represent the greatest percentage increase of all WHO regions.

Global decline in deaths from communicable diseases, but still a major challenge in low- and middle-income countries

In 2019, pneumonia and other lower respiratory infections were the deadliest group of communicable diseases and together ranked as the fourth leading cause of death. However, compared to 2000, lower respiratory infections were claiming fewer lives than in the past, with the global number of deaths decreasing by nearly half a million.

This reduction is in line with a general global decline in the percentage of deaths caused by communicable diseases. For example, HIV/AIDS dropped from the 8th leading cause of death in 2000 to the 19th in 2019, reflecting the success of efforts to prevent infection, test for the virus and treat the disease over the last two decades. While it remains the fourth leading cause of death in Africa, the number of deaths has dropped by more than half, falling from over 1 million in 2000 to 435 000 in 2019 in Africa.

Tuberculosis is also no longer in the global top 10, falling from 7th place in 2000 to thirteenth in 2019, with a 30% reduction in global deaths. Yet, it remains among the top 10 causes of deaths in the African and South-East Asian regions, where it is the 8th and 5th leading cause respectively. Africa saw an increase in tuberculosis mortality after 2000, though this has started to decline in the last few years.

The new estimates also emphasize the toll that communicable diseases still take in low-income countries: 6 of the top 10 causes of death in low-income countries are still communicable diseases, including malaria (6th), tuberculosis (8th) and HIV/AIDS (9th). Meanwhile, in recent years, WHO reports highlight an overall concerning slow-down or plateauing of progress against infectious diseases like HIV, tuberculosis and malaria.

People are living longer – but with more disability

The estimates further confirm the growing trend for longevity: in 2019, people were living more than 6 years longer than in 2000, with a global average of more than 73 years in 2019 compared to nearly 67 in 2000. But on average, only 5 of those additional years were lived in good health.

Indeed, disability is on the rise. To a large extent, the diseases and health conditions that are causing the most deaths are those that are responsible for the greatest number of healthy life-years lost. Heart disease, diabetes, stroke, lung cancer and chronic obstructive pulmonary disease were collectively responsible for nearly 100 million additional healthy life-years lost in 2019 compared to 2000.

Injuries are another major cause of disability and death: there has been a significant rise in road traffic injuries in the African region since 2000, with an almost 50% increase in both death and healthy life-years lost. Similar but slightly smaller increases (at around 40%) were also observed for the Eastern Mediterranean region. Globally, deaths from road traffic injuries are 75% male.

In the Americas, drug use has emerged as a significant contributor to both disability and death. There was a nearly threefold increase in deaths from drug use disorders in the Americas between 2000 and 2019. This region is also the only one for which drug use disorder is a top 10 contributor to healthy life-years lost due to premature deaths and disability, while in all other regions, drug use does not make the top 25.

Data sources and methodology

WHO’s Global Health Estimates present comprehensive, comparable and transparent time-series data for population health, including life expectancy, healthy life expectancy, mortality and morbidity, and burden of disease at global, regional and country levels disaggregated by age, sex and cause, from 2000 onwards.

“These estimates are produced using data from the best available sources from countries and the international community,” said Dr Bochen Cao, the technical lead for WHO’s Global Health Estimates. “They are based on robust scientific methods for the processing, synthesis and analysis of data. These updated estimates also benefited from the valuable contributions of WHO’s Member States through active country consultation and dialogue.” Cao said.

The availability of services to prevent, diagnose and treat disease is key to reducing death and disability, influencing where different conditions are ranked. These new estimates clearly indicate where additional investments in services are most urgently needed.

“Robust health data are critical to address inequalities, prioritize policies and allocate resources to prevent disability and save lives,” adds Dr Samira Asma, Assistant Director-General for the Division of Data, Analytics and Delivery for Impact at WHO. “The WHO Global Health Estimates are a powerful tool to maximize health and economic impact. We call upon governments and stakeholders to urgently invest in data and health information systems to support timely and effective decision-making.” Asma said.

As of today, COVID-19 has tragically claimed more than 1.5 million lives. People living with pre-existing health conditions (such as heart disease, diabetes and respiratory conditions) are at higher risk of complications and death due to COVID-19.

Health authorities worldwide depend on timely, reliable and actionable data to make informed decisions – this is especially true during a global pandemic. The next update to these estimates will include an assessment of the direct and indirect impact of the COVID-19 pandemic on mortality and morbidity.