Cough in a four-month-old baby

Contact your baby's clinician promptly for advice because infants can worsen faster than older children. Seek emergency help now if the baby struggles to breathe, develops blue or grey lips, has pauses in breathing, is difficult to wake or cannot feed.

A viral respiratory infection may cause cough with a blocked or runny nose. Bronchiolitis can present with cough followed by faster, noisier or more effortful breathing and reduced feeding. Reflux may trigger coughing around feeds, but breathing difficulty should never be assumed to be reflux.

Notice when the cough began, whether it comes in spells, and whether there is wheezing, a harsh noise when breathing in, fever, vomiting or choking. Also track feeds and wet nappies; these details help a clinician assess breathing and hydration.

Offer the baby's usual breast milk or formula in smaller, more frequent feeds if congestion makes feeding tiring. Saline nose drops and gentle suction before feeds may clear nasal mucus. Keep the baby away from smoke, vaping aerosols, incense and strong fragrances.

Put the baby to sleep flat on their back on a firm, clear sleep surface. Do not prop the mattress or use pillows. Avoid honey, over-the-counter cough and cold products, menthol rubs and medicines not specifically prescribed for the baby.

Get emergency care for ribs pulling in with breaths, grunting, marked nostril flaring, blue or grey colour, pauses in breathing, limpness, unusual difficulty waking, or choking with sudden breathing trouble. A baby who is too breathless to feed also needs immediate assessment.

Seek same-day medical advice for fever, worsening cough, wheeze, repeated vomiting, fewer wet nappies, dry mouth, poor feeding or unusual sleepiness. Mention premature birth and any heart, lung or immune condition because these can affect how the baby is assessed.

Tell the clinician how the breathing looks between coughs, how much the baby is feeding, whether wet nappies have changed and whether anyone nearby is ill. Ask what changes should trigger reassessment and whether nasal saline is appropriate for your baby.