One diagnostic database counted 497 separate causes of breathlessness
Feeling short of breath is a single sensation with a staggering list of possible origins. An online medical expert system tallied 497 distinct causes in 2010, spanning heart, lungs, nerves, blood and mind. Yet a handful of conditions, from asthma to heart failure to panic, account for about 85 percent of cases.
Doctors call it dyspnoea, and the American Thoracic Society treats it as a subjective experience made of distinct sensations: the effort of breathing, tightness in the chest and air hunger, the feeling of not getting enough oxygen. It is perfectly normal during hard exercise. It becomes a warning sign when it appears at rest or with light activity. Because it is subjective, it does not always match objective measures; in long COVID, where it is one of three major symptoms, breathlessness does not track markers of inflammation.
Clinicians sort causes in several ways. One scheme separates heightened awareness of normal breathing, as in anxiety, from extra work of breathing and from faults in the respiratory system itself. Timing is another clue. A sudden onset points towards events such as a collapsed lung, a clot in the lungs or a heart attack, while COPD and pulmonary fibrosis bring a slow, creeping decline punctuated by flare-ups. Asthma tends to come in episodes linked to triggers such as colds or allergens.
Some numbers show the scale. Asthma affects around 5 percent of people and is the commonest reason for arriving at an emergency department short of breath. Congestive heart failure touches 1 to 2 percent of Americans and 10 percent of those over 65. Around two-thirds of women feel breathless during a normal pregnancy. Gradual anaemia can bring breathlessness on exertion along with fatigue and a racing heart.
The mind plays a real part. Panic attacks commonly include shortness of breath and hyperventilation, though panic is usually diagnosed only after other causes are excluded. A pattern called sigh syndrome involves repeated attempts at a deep breath followed by long audible sighs; it is not dangerous and usually settles by itself. In advanced cancer, moderate evidence suggests that simply moving air across the face with a handheld fan eases the sensation, while a review found opioids and anti-anxiety drugs no better than placebo for that group.
Source: Shortness of breath
