The doshas may change their proportional balance as the result of a variety of factors, including inappropriate lifestyle and activities, diet, and mental or physical trauma. Many poor lifestyle choices are due to our lack of understanding about our own bodies. When there is a change to our dosha balance taking place within us, still pre-clinical in its development, it may take a very long period of time for signs and symptoms to appear. Very often as these changes occur, disease will take a path along the inherited weak areas of the individual. In some cases, a disease will manifest in the body beyond the individual's control. This is known as a "karmic disease," based on the theory of cause and effect.