Jennifer Mendoza
Research expert covering health, pharma and medtech
Diseases - Statistics & Facts
In 2021, the leading causes of death worldwide included diseases such as heart disease, COVID-19, chronic obstructive pulmonary disease, and cancer. At that time, ischemic heart disease resulted in just over nine million deaths, while COVID-19 caused 8.7 million, and lung cancer, the deadliest form of cancer, accounted for 1.86 million deaths. There are several ways to classify diseases, but they can most easily be divided into communicable or infectious diseases and non communicable or chronic diseases. Communicable diseases such as malaria, tuberculosis, and HIV, can be transmitted between people, while chronic diseases like heart disease, cancer, and diabetes, cannot spread from one person to another. As of 2021, tuberculosis was the deadliest communicable disease in the world, causing almost 1.4 million deaths. The burden of different diseases can vary greatly from country to country depending on the region and income level.
How does income level impact the burden of disease?
When looking at the leading causes of death in high-income and low-income countries there is one clear difference. High-income countries are much more impacted by chronic diseases while low-income countries struggle more with infectious diseases. For example, in 2021, among the ten leading causes of death in low-income countries were malaria, diarrheal diseases, tuberculosis, and HIV/AIDS. However, none of these infectious diseases were in the leading ten causes of death in high-income countries at that time. On the other hand, chronic diseases such as Alzheimer's disease, chronic obstructive pulmonary disease (COPD), and lung cancer were among the leading causes of death in high-income countries, but not in low-income countries. However, chronic diseases such as heart disease, cancer, and diabetes are prevalent in low-and middle-income countries and are becoming increasingly common. For example, it is estimated that between 2024 and 2050, the number of diabetics in Africa will increase by around 142 percent, while in South-East Asia the total number of people with diabetes could reach over 184 million.Common diseases in the United States
The leading causes of death in the United States are mostly chronic diseases such as heart disease, cancer, cerebrovascular diseases, chronic lower respiratory diseases, Alzheimer's disease, and diabetes. In the year 1900, the leading three causes of death in the U.S. were pneumonia/influenza, tuberculosis, and gastrointestinal infections, all infectious diseases that are no longer among the ten leading causes of death in the country. Rates of death from several major chronic diseases such as heart disease and stroke have decreased in recent years, however, the number of deaths due to Alzheimer's disease increased by over 140 percent from the year 2000 to 2022, and it is now the sixth leading cause of death in the United States. As the elderly population in the U.S. continues to grow so will the burden of Alzheimer's disease, with cases expected to reach over 11 million by the year 2040.
