In 2021, the top 10 causes of death accounted for 39 million deaths, or 57% of the total 68 million deaths worldwide. The main causes of death were primarily associated with cardiovascular diseases like ischaemic heart disease and stroke, as well as respiratory illnesses such as COVID-19, chronic obstructive pulmonary disease, and lower respiratory infections. COVID-19 emerged as the second leading cause of death globally, highlighting the devastating impact of the pandemic on global health.
Causes of death can be categorized into three main groups: communicable diseases, noncommunicable diseases, and injuries. At a global level, 7 out of the top 10 causes of death in 2021 were noncommunicable diseases, accounting for 38% of all deaths. Ischaemic heart disease was the leading cause of death worldwide, responsible for 13% of total deaths. The number of deaths from this disease has been steadily increasing since 2000, reaching 9.1 million deaths in 2021.
COVID-19, as a newly emerged cause of death, directly accounted for 8.8 million deaths in 2021, pushing down other leading causes of death by one place. Stroke and chronic obstructive pulmonary disease, which were among the top causes of death in 2019, became the third and fourth leading causes of death in 2021. Lower respiratory infections remained the most deadly communicable disease other than COVID-19, claiming 2.5 million lives in 2021.
Other noncommunicable diseases that saw an increase in deaths in 2021 include trachea, bronchus and lung cancers, Alzheimer’s disease, and diabetes. However, diseases like HIV and AIDS and diarrhoeal diseases have seen a decrease in deaths since 2000.
When looking at leading causes of death by income group, low-income countries were more likely to experience deaths from communicable diseases, with malaria, tuberculosis, and HIV/AIDS remaining in the top 10 causes of death. In contrast, high-income countries saw a rise in deaths from diseases like Alzheimer’s disease and diabetes, reflecting the impact of aging populations.
Understanding the reasons people die is crucial for improving public health and directing resources where they are needed most. By collecting and analyzing data on causes of death, we can better assess the effectiveness of health systems and allocate resources accordingly. The World Health Organization develops standards and best practices for data collection to ensure accurate and timely reporting of mortality data.
In conclusion, knowing the leading causes of death globally and by income group is essential for improving health outcomes and reducing deaths worldwide. By addressing these key health issues, we can work towards a healthier and more resilient global population.
