Over the years, a wide variety of respiratory diseases have caused a high mortality rate throughout the world. This was again observed with the appearance of the pandemic, COVID-19. In addition, the most affected are people living in extreme poverty. The objective is design a mobile health application for the registration and diagnosis of respiratory diseases. For this, the RUP methodology was applied, because it easily adapts to various types of projects. Its use, together with the UML process development software, allows the analysis, implementation and documentation of object oriented systems. For validation, a user survey was carried out and the questionnaire was based on the dimensions of functionality, efficiency, effectiveness and satisfaction. Obtaining as a result a positive qualification to the design of the application and its acceptance due to the reduction in the time to obtain the diagnosis. In conclusion, a mobile health application design was successfully carried out so that patients can register and have the diagnosis of respiratory diseases from the comfort of their home