Getting asthma onto the global agenda for health and poverty reduction Asthma is one of the most common chronic diseases in the world, currently affecting an estimated 300 million people worldwide. It has been identified as a major global public health problem and international guidelines exist. However, in low- and middle-income countries, where the majority of the world's asthmatics live, most cases of asthma are undiagnosed, untreated or mismanaged.