The Full form of SOB is Shortness of Breath. SOB means difficulty in breathing. Medically, it is referred to as dyspnea. Shortness of Breath can be caused by respiratory (breathing passages and lungs) or circulatory (heart and blood vessels) conditions and other conditions such as severe anemia or high fever. An average 150-pound (70 kg) adult will breathe at an average rate of 14 breaths per minute at rest. Excessively rapid breathing is referred to as hyperventilation and Shortness of Breath is referred to as dyspnea. Causes of shortness of breath include asthma, pneumonia, pneumothorax, bronchitis, anemia, inhalation injury, pulmonary embolism, lung cancer, anxiety, COPD, congestive heart failure, high altitude with lower oxygen levels, arrhythmia, allergic reaction, interstitial lung disease, obesity, tuberculosis, epiglottitis, emphysema, anaphylaxis, subglottic stenosis, pulmonary fibrosis, croup, polymyositis, pulmonary artery hypertension, pleurisy, Guillain-Barré syndrome, sarcoidosis, rib fracture, carbon monoxide poisoning, and aerobic exercise. SOB can be associated with symptoms of chest pain, pain with inspiration (pleurisy), dizziness, fainting, anxiousness, fatigue, cough, neck pain, wheezing, bloody sputum, and chest injury. Doctors will classify dyspnea as either occurring at rest or being associated with activity, exercise, or exertion. Each of these symptoms helps to detect the precise cause of the SOB.