What should you know about unexplained shortness of breath?

Breathlessness may appear during activity, at rest, when lying down, or alongside wheezing, cough, chest discomfort, palpitations, fever, or tiredness. Causes can include asthma, acute bronchitis, COPD, bronchiectasis, anaemia, angina, or an irregular heart rhythm such as atrial fibrillation. A severe allergic reaction can also restrict breathing. The symptom alone cannot identify its cause, and a breathing problem is not proof of any one condition.

Arrange a clinical assessment if breathlessness is new, recurring, getting worse, or limiting ordinary activity. Note when it began, what brings it on, whether it improves with rest, and any medicines, allergies, recent infection, smoking or vaping, travel, and known heart or lung conditions. Sit upright, loosen tight clothing, and use a prescribed reliever medicine only as directed. Avoid strenuous activity until you understand the cause.

Seek emergency help for severe or rapidly worsening breathlessness, blue or grey lips, confusion, fainting, inability to speak in full sentences, sudden chest pressure, or swelling of the face, lips, tongue, or throat. Urgent assessment is also needed when breathlessness follows a possible allergic exposure or comes with coughing blood, sudden weakness, or a very fast or irregular heartbeat.

Could my symptoms relate to my lungs, heart, blood count, or medicines? Do I need breathing tests, heart checks, or blood tests? Which changes should prompt emergency care? What activity is safe while this is being assessed?