Shortness of Breath (Dyspnea)

Shortness of breath has many causes affecting either the breathing passages and lungs or the heart or blood vessels. An average 150-pound (70 kilogram) adult will breathe at an average rate of 14 breaths per minute at rest. Excessively rapid breathing is referred to as hyperventilation. Shortness of breath is also referred to as dyspnea.

Doctors will further classify dyspnea as either occurring at rest or being associated with activity, exertion, or exercise. They will also want to know if the dyspnea occurs gradually or all of a sudden. Each of these symptoms help to detect the precise cause of the shortness of breath.

Causes of shortness of breath include asthma, bronchitis, pneumonia, pneumothorax, anemia, lung cancer, inhalation injury, pulmonary embolism, anxiety, COPD, high altitude with lower oxygen levels, congestive heart failure, arrhythmia, allergic reaction, anaphylaxis, subglottic stenosis, interstitial lung disease, obesity, tuberculosis, epiglottitis, emphysema, pulmonary fibrosis, pulmonary artery hypertension, pleurisy, croup, polymyositis, Guillain-Barré syndrome, sarcoidosis, rib fracture, carbon monoxide poisoning, and aerobic exercise.

Shortness of breath can be associated with symptoms of

• anxiousness,
• bloody sputum,
• chest injury,
• chest pain,
• chest tightness,
• cough,
• dizziness,
• fainting,
• fatigue,
• heart palpitations,
• labored breathing,
• neck pain,
• pain with inspiration (pleurisy),
• rapid, shallow breathing, and
• wheezing.

Other causes of shortness of breath

• Chest Wall & Chest Muscle Diseases
  Numerous diseases of muscles and the nervous system can lead to shortness of breath by weakening the body's capacity for opening the lungs up for respiration. Examples of muscle diseases include muscular dystrophy. Nervous system diseases, such as paralysis, can lead to shortness of breath.
• Heart Diseases
  Many conditions that affect the heart and its capacity to move blood through the lungs can lead to shortness of breath. These conditions include valve diseases of the heart and others.
• Lung Tissue Diseases
  There are a vast number of lung tissue diseases ranging from common and temporary, to uncommon and chronic. These include infections (pneumonia, acute bronchitis from bacteria, viruses, etc.), cancers that have spread to the lung, chemical and radiation toxicity to the lung (including radiation therapy), occupational toxicities (such as minerals from mines), hemosiderosis, fungus infections (coccidiomycosis, blastomycosis, aspergillosis), allergic reactions, drug toxicity, connective tissue diseases, and many others.
• Obstructions to Airflow
  Obstruction to airflow can occur anywhere along the passageway that the air we breathe takes from entering the nose and mouth, through the trachea (windpipe in our throats), through the bronchial tubes and tiny airways in the lungs. Sudden blockage of airways is a medical emergency and can be caused by inhaling objects, food particles or fluids.
• Other Causes
  Acidosis, such as from salicylate (aspirin) poisoning. Low oxygen environment, such as at high altitudes.