What should you know about unexplained wheezing?

Wheezing often comes from the small airways in the lungs. Asthma can cause episodes after exercise, cold air, allergens or respiratory infections. Acute bronchitis may irritate the airways during a chest infection. Allergic rhinitis can add nasal congestion and trigger airway symptoms. COPD is another possible cause, particularly in people with a history of smoking or long-term exposure to irritants. In young children, bronchiolitis can produce noisy breathing. A sudden episode after food, medicine or an insect sting may indicate anaphylaxis and needs emergency attention. A wheezing sound does not identify one diagnosis by itself.

Notice when the sound occurs, whether it is on breathing in or out, and whether you also have cough, fever, chest tightness or reduced exercise tolerance. Avoid smoke, strong fragrances and other triggers while arranging an assessment. A clinician may listen to your chest, check oxygen levels and review allergies, medicines and previous breathing problems. Treatment depends on the cause; a nebuliser treatment may be considered when inhaled medicine is needed in an acute setting.

Call emergency services if wheezing comes with severe breathlessness, blue or grey lips, faintness, swelling of the face or throat, difficulty speaking, or a rapidly worsening reaction. Seek same-day medical care for new wheezing with chest pain, high fever, confusion, or marked difficulty breathing. Arrange a routine appointment when wheezing keeps returning, wakes you at night, or lasts beyond a respiratory illness.

Could my medicines, allergies or a recent infection be narrowing my airways? Do I need breathing tests or an inhaler review? Which symptoms should prompt emergency help, and how should I manage a future episode?