What is the known number of diseases?

As of 2022, it is estimated that there are between 100,000 and 200,000 different types of diseases that affect humans. This includes both infectious and non-infectious diseases.

The World Health Organization (WHO) has identified over 100,000 diseases, while the National Center for Biotechnology Information (NCBI) has catalogued over 200,000 diseases. However, it is important to note that not all of these diseases are well-known or widespread.

Some of the most common diseases in the world include:

* Cancer

* Cardiovascular diseases (such as heart disease and stroke)

* Chronic respiratory diseases (such as asthma and chronic obstructive pulmonary disease)

* Diabetes

* Mental disorders (such as depression and anxiety)

* Infectious diseases (such as influenza, HIV/AIDS, and malaria)

The number of diseases is constantly changing as new diseases are discovered and old diseases are eradicated or become less common.