Dry Cough: Causes and How to Stop It

What a dry cough is

Coughing is a reflex that protects the airways. Sensors in the throat, voice box and airways detect irritation and trigger a forceful blast of air. In a productive (wet) cough, the cough brings up mucus. In a dry cough, there is little or no mucus. The irritation is from inflammation, sensitive nerves or something tickling the throat.

Dry coughs often feel like a tickle or scratch at the back of the throat, come in fits, and get worse when you talk, laugh, breathe cold air or lie down.

How long does a dry cough last?

Common causes of a dry cough

Viral infections

Colds, flu and COVID-19 commonly cause a dry cough along with a sore throat, runny nose and sometimes fever. COVID-19 classically causes a dry cough with fever and tiredness.

Post-viral cough

After a respiratory infection, the airways can stay inflamed and oversensitive for weeks. The cough is dry, tickly and often worse at night, while you otherwise feel well. It gradually fades, usually within 3 to 8 weeks.

Allergies and post-nasal drip

Allergic rhinitis (hay fever) causes a dry cough together with a runny nose, sneezing, itchy watery eyes and an itchy throat. Mucus dripping down the back of the throat (post-nasal drip) triggers the cough. There is no fever. It often follows a seasonal pattern or happens around pets or dust.

Asthma

Asthma can cause a dry cough that is worse at night, early morning, with exercise, cold air or allergens. Some people have a cough as their only symptom, called cough-variant asthma. Wheezing, chest tightness and breathlessness may come and go.

Acid reflux

Stomach acid reaching the throat or tiny amounts breathed in can irritate the airways. A reflux cough is often worse after meals, when lying down, or with talking, and may come with heartburn, a sour taste, hoarseness or frequent throat clearing. Many people have no heartburn at all. See GERD.

Blood pressure medicines (ACE inhibitors)

ACE inhibitors such as lisinopril, enalapril and ramipril cause a persistent dry, tickly cough in roughly 1 in 10 people who take them. It can start weeks or months after starting the medicine and usually stops within 1 to 4 weeks of switching, occasionally longer. Do not stop the medicine without speaking to your doctor.

Irritants

Smoke, vaping, dust, strong fumes, dry air and air pollution all irritate the throat.

Less common and serious causes

• Whooping cough (pertussis): weeks of violent coughing fits, sometimes with a "whoop" on breathing in and vomiting afterward. Dangerous in babies.
• Laryngitis and vocal cord problems: hoarseness with a dry cough.
• Interstitial lung disease (lung scarring): a persistent dry cough with gradually worsening breathlessness and crackles heard in the lungs.
• Heart failure: dry cough worse lying flat, with breathlessness and swollen ankles.
• Lung cancer: a new or changed cough in a smoker or ex-smoker, coughing blood, weight loss or hoarseness.
• Pulmonary embolism: sudden breathlessness, chest pain and sometimes a dry cough or coughing blood.
• Tuberculosis: cough for more than 3 weeks with fever, night sweats and weight loss.
• Something inhaled: sudden cough in a child after choking.

Dry cough at night

Night coughs are typical of post-nasal drip (mucus pools when lying down), asthma (airway inflammation peaks in the early hours), reflux (acid travels up more easily) and heart failure. Raising the head of the bed, avoiding food for 3 hours before bed, and treating allergies or asthma often helps.

How doctors find the cause

For a cough under 3 weeks with a clear cold, no tests are usually needed. For a longer cough, your doctor will ask about smoking, medicines, allergies, heartburn, wheeze and other symptoms, and examine your nose, throat and chest. Tests may include:

• chest X-ray for any cough lasting more than 8 weeks, or sooner with warning signs
• spirometry and sometimes a FeNO test for asthma
• blood tests and allergy tests
• trial treatments, such as a nasal steroid for post-nasal drip, asthma inhalers, or acid suppression, to see what helps
• CT scan or referral to a specialist if the cause is unclear

Dry cough remedies

• Honey: 1 to 2 teaspoons, alone or in warm water or tea, eases cough and helps sleep. Never give honey to babies under 12 months.
• Warm drinks: soothe the throat and reduce the tickle.
• Lozenges or hard candy for adults and older children (not for young children, who may choke).
• Humidified air or a steamy shower, especially in dry, heated rooms.
• Avoid smoke and irritants, and stop smoking or vaping.
• Raise your head at night with an extra pillow.
• Saline nasal spray or a non-drowsy antihistamine if allergies or post-nasal drip are involved.

Over-the-counter cough suppressants containing dextromethorphan may modestly help some adults. Follow the label dose. Cough and cold medicines are not recommended for children under 6 in the US. Antibiotics do not help a viral cough.

Treating the cause is the long-term fix: inhalers for asthma, a nasal steroid spray for allergic rhinitis, lifestyle changes and acid-reducing medicine for reflux, and switching an ACE inhibitor to another medicine.

Frequently asked questions

What causes a dry cough with no mucus?

The most common causes are viral infections, a lingering post-viral cough, allergies with post-nasal drip, asthma, acid reflux and ACE inhibitor medicines. Smoke, dry air and other irritants can also cause it. A cough lasting more than 3 weeks should be checked.

Can allergies cause a dry cough with a runny nose?

Yes. Allergic rhinitis causes a runny nose, sneezing and itchy, watery eyes, and the mucus dripping down the back of the throat triggers a dry, tickly cough. There is no fever. Antihistamines and a steroid nasal spray usually help.

How long does a dry cough last after a cold?

A dry cough often outlasts the cold by 1 to 3 weeks and can occasionally last up to 8 weeks as the airways recover. See a doctor if it lasts more than 3 weeks, gets worse, or comes with breathlessness, fever, chest pain or blood.

How do I stop a dry cough at night?

Raise your head with an extra pillow, take a spoonful of honey before bed (not for babies under 1), keep the room humidified, and avoid eating late if reflux may be involved. If the cough persists, asthma, allergies or reflux may need specific treatment.

Is a dry cough a sign of COVID-19?

It can be. COVID-19 often causes a dry cough with fever, tiredness, sore throat or loss of smell. But colds, flu and allergies cause similar coughs. A home test can help tell them apart.