Night-time cough: causes, red flags and when to get it checked

Several things change when you lie down: gravity no longer helps drain mucus from the nose, acid can reflux more easily, fluid shifts into the chest, and the airways become more reactive in the early hours. Each produces a night cough with its own accompanying symptoms.

• Postnasal drip from allergic rhinitis, sinusitis or a cold, with throat clearing and a blocked nose.

• Asthma, including cough-variant asthma, with night cough, wheeze, chest tightness and triggers such as allergens and cold air.

• Gastro-oesophageal reflux, with heartburn, a sour taste and worse symptoms lying flat or after meals.

• Post-viral airway sensitivity after a chest infection.

• ACE inhibitor medicines and smoking.

• Heart failure: cough with breathlessness lying flat, waking at night breathless and swollen ankles.

• COPD and bronchiectasis, with phlegm on waking.

• Sleep apnoea, lung cancer and, rarely, aspiration of food or drink.

Coughing up blood, weight loss, night sweats, breathlessness at rest, orthopnoea (needing extra pillows), swollen ankles, fever, pink frothy sputum or choking episodes at night are warning signs.

• Call 999: severe breathlessness, coughing blood in quantity, blue lips or chest pain.

• Same-day GP: waking breathless at night with leg swelling, fever with productive cough, or night cough with weight loss.

• GP within a week or two: persistent night cough over three weeks with wheeze or reflux.

• Routine: night cough with a cold that is improving.

Questions cover timing, wheeze, nasal symptoms, heartburn, meals, pillows, smoking, medicines, allergy history, weight change and fevers. Examination includes the nose and throat, chest, heart, oxygen level and ankles.

• Peak flow diary and spirometry: for asthma.

• Chest X-ray: for lung and heart abnormalities.

• NT-proBNP and echocardiogram: if heart failure is suspected.

• Allergy tests: if rhinitis or asthma is linked to allergens.

• Trial of acid suppression or an endoscopy: for reflux-related causes.

Raise the head of the bed, avoid eating for three hours before bed, keep the bedroom cool and dust-free, and use saline rinses for postnasal drip. Stop smoking, and wash bedding regularly. Take asthma inhalers as prescribed. Honey in warm water can soothe a throat cough in adults.

The NHS route is a GP with asthma review, reflux treatment trials or heart tests. Private respiratory, gastroenterology and cardiology consultations are accessible directly.