Lung conditions that cause shortness of breath

Asthma often causes variable breathlessness, wheeze or chest tightness. COPD may cause ongoing breathlessness and cough, while bronchiectasis can bring breathlessness with repeated chest infections and phlegm. Acute bronchitis may cause a temporary cough and uncomfortable breathing, commonly after an infection.

Breathlessness can also arise from anaemia, heart conditions such as angina or atrial fibrillation, or a severe allergic reaction. These possibilities can overlap, so the symptom pattern, examination, oxygen level and selected tests matter more than a label guessed at home.

Book a clinical assessment if breathlessness is new, persistent, recurrent or limiting ordinary activity. Record when it happens, whether lying down or exertion changes it, and any cough, fever, wheeze, chest pain, palpitations or leg swelling. Bring a list of medicines and inhalers.

Use prescribed breathing medicines as directed. Avoid smoke and strong fumes, and rest between activities while awaiting advice. Do not assume that an antibiotic or inhaler is appropriate without knowing the cause.

Get emergency help for severe or sudden breathlessness, blue or grey lips, fainting, confusion, sudden chest pain, coughing blood, or swelling of the lips, tongue or throat. Rapid worsening after a possible allergen is also an emergency. A gradual but clear decline still deserves prompt medical review.

Which features point toward a lung, heart or blood-related cause? Do I need oxygen measurement, breathing tests, imaging or blood tests, and what should I do if symptoms change?