What causes shortness of breath?

Breathlessness with wheezing may occur when the airways narrow, as in COPD. Cough and fever can accompany pneumonia or COVID-19. Reduced pumping by the heart can cause breathlessness with activity or when lying flat. Iron deficiency anaemia can reduce the blood’s ability to carry oxygen, while anxiety can produce rapid breathing and a tight-chested feeling. A pulmonary embolism may cause sudden breathlessness, chest pain, or a fast heartbeat. The timing, triggers, and other symptoms help a clinician narrow the cause.

Stop strenuous activity, sit upright, loosen tight clothing, and use a prescribed reliever inhaler according to your action plan. Note whether symptoms began suddenly, follow exertion, occur at rest, or come with cough, fever, pain, swelling, or palpitations. Arrange medical review for new, persistent, or worsening breathlessness, even if it settles. Do not start someone else’s inhaler or antibiotics.

Call emergency services for severe or sudden breathlessness, blue or grey lips, inability to speak in full sentences, fainting, confusion, severe chest pain, or coughing blood. Sudden breathlessness after prolonged immobility, surgery, or travel also needs urgent assessment because a clot may be involved.

What pattern does my breathing problem suggest? Do I need an oxygen check, chest examination, blood tests, or imaging? Which symptoms require emergency care? Could a medicine, anaemia, anxiety, or heart problem contribute?