Two large studies: ISAAC and ECRHS have provided an extensive volume of data on the epidemiology of asthma worldwide. Several other, more local population studies, also give us important information, unfortunately their methodology is not always comparable.

In Western Europe, almost 30 million individuals now suffer from asthma and the prevalence rate has doubled over the last decade. However, in some populations dynamic of asthma morbidity seems to have reached plateau recently. The highest prevalence of asthma in children and in adults are found in English-speaking countries (Great Britain >15%, New Zealand 15,1%, Australia 14,7%, the Ireland 14,6% and Canada 14,1%). In USA 31,3 mln people suffer from asthma: 22,1 mln adults and 9,2 mln children (data from 2001). The lowest prevalence is found in Asia (China) and Oceania.

It is estimated that asthma accounts for about 1 in every 250 deaths worldwide. Fatality rate (asthma deaths per 100 000 asthmatics) is highest in Asia (China 36,7/100 000). In Europe this rate is highest in Albania 20,8/100 000 and Romania (14,7/100 000). In USA the fatality rate is within mean values (5,2/100 000). High fatality rates are also reported in Mexico (14,5/100 000), Colombia (10,1/100 000) and South Africa (18,5/100 000). Polish Multicenter Study of Epidemiology of Allergic Diseases has shown mean prevalence in adults in Poland approximately 5,4% and in children approximately 8,6%.