Shortness of breath is classified as physiological or organic.
When mental, emotional or prolonged exposure to an abnormal environment causes discomfort in the body, it can manifest as shortness of breath.
When various causes lead to respiratory dysfunction, cardiac decompensation or other chronic diseases, it can also cause shortness of breath, which has to be judged in combination with other accompanying symptoms. Common diseases include: chronic obstructive pulmonary disease, pleural effusion, pulmonary oedema, thoracic deformity, pneumothorax, bronchial asthma, pulmonary embolism, pulmonary hypertension, myocardial ischaemia, anaemia, massive abdominal effusion, hypothyroidism, and neurosis.