A computerized method and system for measuring a user's lung capacity and stamina, to detect Chronic Heart Failure, COPD or Asthma, comprising: providing a client application on a user's mobile communication device, said client application comprising executable computer code for: instructing the user to fill his lungs with air and utter vocal sounds within a certain range of loudness (decibels) while exhaling； receiving and registering by the mobile communication device said user's vocal sounds； stopping the registering of vocal sounds； measuring the length of the vocal sounds receiving time within said range of loudness, said time proportionate the user's lung volumes； and displaying the length of sound received time results on the mobile communication device screen.
