Breathing difficulties can be described in several different ways. You may be short of breath, unable to take a deep breath, gasping for air, or feel like you are not getting enough air.

See also: Choking

If you are having difficulty breathing, it is almost always a medical emergency (other than feeling slightly winded from normal activity like exercise or climbing a hill).

Difficulty breathing has many potential causes. Some of the most common are:

• Collapsed lung, which can happen if you have emphysema or asthma, but may also happen spontaneously in young, healthy people
• Heart attack
• Heart disease, asthma, emphysema, chronic bronchitis, or heart failure
• High altitudes, which can be a problem even in young people
• Injury to the neck, chest wall, or lungs
• Life-threatening allergic reaction
• Pulmonary embolism, or a blood clot in the lung, which can cause very abrupt and severe difficulty breathing
• Sudden illness or infections like pneumonia, acute bronchitis, whooping cough, croup, or epiglottitis