Shortness of breath: what it may mean

Shortness of breath can come from the lungs, heart, blood, muscles or a sudden allergic reaction, so its pattern and severity guide assessment. Breathlessness during exertion may differ from breathlessness at rest, and a new symptom deserves attention even when it comes and goes. It cannot be diagnosed safely from the sensation alone.

Wheeze, cough and chest tightness can occur when airways narrow, as in asthma or acute bronchitis. Long-term mucus and repeated chest infections may occur with bronchiectasis or COPD. Breathlessness with palpitations can accompany atrial fibrillation, while chest pressure brought on by exertion can be associated with angina. Anaemia can reduce oxygen delivery and cause tiredness with exertion. Anaphylaxis can cause sudden breathing difficulty with swelling, rash or throat tightness.

Stop the activity, sit upright and loosen restrictive clothing. Note when the symptom began, what triggered it, whether it occurs at rest and whether cough, fever, wheeze, pain, swelling or palpitations accompany it. Use a prescribed reliever only according to your action plan. Arrange clinical review for new, recurring or unexplained breathlessness, even if it settles.

Call emergency services for severe or sudden breathlessness, blue or grey lips, fainting, confusion, severe chest pain, facial or tongue swelling, or difficulty speaking in full sentences. Get urgent help if symptoms rapidly worsen or begin after a possible allergen. Do not drive yourself if you feel faint or severely short of breath.

Ask what examination or breathing tests you need, whether medicines or allergies could contribute, how to recognise your personal warning signs and what action plan to follow if breathlessness returns.