Respiration, the most vital human process, is affected due to the development of a virus that has become deadly, called Covid-19, and leads to millions of deaths worldwide, due to the alterations it produces in the respiratory function, resulting in sequelae of the same origin and thus decreasing the quality of life of people who acquire this pathology. For this reason, it is reasonable that a thorough evaluation is made in order to better understand and define the disease and provide a better multidisciplinary treatment, also, integrating the patient to a self-knowledge to strengthen their Immune System. Taking into account the techniques that we can use for its execution, this book uses spirometry as a means of evaluation, in this way we were able to observe how the respiratory function of post Covid patients is and the level of severity that it seeks.