Persistent cough: causes, treatment by video and when to worry

Doctors group coughs by how long they last:

• Acute cough: starts suddenly, usually from a cold, flu or sinus infection, and generally goes away within 3 weeks.
• Subacute cough: lasts 3 to 8 weeks, often the cough left behind after an infection.
• Chronic cough: lasts more than 8 weeks and always deserves a medical evaluation.

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The causes table on this page sums up the usual suspects. A few clues:

• Cough with fever and body aches: flu or COVID-19.
• A wet cough that lingers after a cold: possibly bronchitis.
• A dry cough with sneezing and itchy nose or eyes: possibly allergies.
• A cough with wheezing, worse at night or with exercise: possibly asthma.
• A cough with heartburn, worse lying down: possibly acid reflux.
• Mucus dripping down the throat and facial pressure: possibly a sinus infection.

A dry cough brings nothing up and is common with allergies, asthma, reflux or the tail end of a cold. A wet (productive) cough usually goes with a respiratory infection. Mucus color alone does not tell you whether you need an antibiotic, and most viral coughs get better without one. Get checked if the mucus is bloody or foul-smelling, or if you have a fever.

For a cough from a cold or flu without warning signs:

• Drink plenty of fluids to help loosen mucus.
• Breathe steam from a warm shower or use a humidifier.
• Cough drops or hard candy can ease a dry cough in adults. Never give them to children under 3, who can choke on them.
• Stay away from cigarette smoke and vaping.
• If you use over-the-counter cough or decongestant products, read the label, especially if you have high blood pressure or another condition.
• If a cough lasts more than 10 to 14 days, comes with fever, or the doctor suspects another cause, she will decide whether you need tests. If needed, she gives you a lab order; if you need an X-ray or an in-person chest exam, she tells you and points you to the right place.

For your safety, call 911 if you are short of breath or struggling to breathe, or have hives with a swollen face or throat and trouble swallowing. Go to the ER if you cough up blood or have chest pain. Get care soon if a cough comes with a high fever, a high-pitched sound when breathing or foul-smelling mucus, gets worse lying down and you have a heart condition, or if you may have been exposed to tuberculosis. See when to go to the ER.

We see children of all ages too; for patients under 21, a parent or legal guardian stays on camera for the whole visit and shows photo ID. Children follow different rules: over-the-counter cough and cold medicines are not recommended under age 4, and honey must not be given to babies under 12 months. Read cough in children.