Why You Cough

Medically Reviewed by Neha Pathak, MD on August 28, 2023
3 min read

Got a cough? Experts say it's the top reason people see a doctor -- more than 30 million visits a year.

Your first step toward relief is to identify the type of cough you have and what is causing it. Then consider your symptoms. With that info, you can choose the best treatment.

A cough is supposed to protect you. It gets out stuff that doesn't belong in your lungs and windpipe, like inhaled dirt or food. But it can also be caused by other things. How long a cough lasts depends on what's causing it.

There are several classifications for coughs. They include:

  • Productive cough. Also called a wet cough, this cough brings up mucus or phlegm.
  • Non-productive cough. This is a dry cough that doesn’t bring up mucus or phlegm.
  • Acute cough. It comes on suddenly and lasts for 2-3 weeks.
  • Subacute cough. This type lingers after you’ve had an infection and can last 3-3 weeks.
  • Chronic cough. This is a cough that lasts 8 weeks or longer and may require medical attention.
  • Refractory cough. This is the name for a chronic cough that hasn’t responded to treatment.

There are many common triggers.

  • Viruses. Colds and the flu are the most common causes. While annoying, coughs that are “productive” get germy mucus out of your lungs when you're sick. Most go away in a few days. After a cold, though, some "dry" coughs last weeks. That could be because coughing irritates your lungs, which leads to more coughing, which irritates your lungs, and so on.
  • Allergies and asthma. If you have them, inhaling a trigger like mold can cause your lungs to overreact. They're trying to cough out what’s bothering them. 
  • Irritants. Even if you're not allergic, things like cold air, cigarette smoke, or strong perfumes can set off a hacking spell.
  • Postnasal drip. When you're congested, mucus drips down from your nose into your throat and makes you cough. You can get postnasal drip from colds, flu, sinus infections, allergies, and other problems.
  • Acid reflux. When you have heartburn, stomach acids back up into your throat, especially at night. They can irritate your windpipe, vocal cords, and throat and make you cough.
  • COPD. This includes one or more of three separate serious conditions: Emphysema, chronic bronchitis, and chronic obstructive asthma. These illnesses weaken the tubes in your airway (bronchial tubes) and the tiny sacs (alveoli) that pass oxygen into your blood and remove carbon dioxide. Cigarette smoking is the most common cause of COPD.
  • Other causes. Many other problems -- lung inflammation, sleep apnea, and drug side effects -- can be triggers. Get coughs that won't go away checked out to make sure you don’t have a separate problem.

That depends on the cause. Options include:

  • Medicines. Over-the-counter cough remedies can help in a number of ways. Suppressants lessen your urge to cough. Expectorants thin mucus and make it easier to hack up.
  • Home remedies. You can drink warm fluids, inhale warm, moist air, and use cough drops. Add a spoonful of honey to hot tea, or choose a cough drop that has it. Never give honey to a child under a year old -- it can make them very sick.
  • Avoid triggers. If you have allergies or asthma, remove allergens from your home. Keep pets out of your bedroom. Use air conditioners to filter air during pollen season. You won’t see the effects right away, but if you stay away from what bothers you, you'll start to feel better.
  • Treatment for another problem. Coughs triggered by asthma, acid reflux, COPD, and other medical conditions need special treatment -- often medicine. Talk to your doctor.
  • Time. Common viruses are the most likely causes. Sometimes, the cough can last weeks or months after the virus is gone. Over time your airways will heal and the cough will stop.

Most lingering coughs are harmless. But you can't figure out the causes on your own. If your cough isn't getting better after 1 week, it's time to call your doctor.

See them as soon as you can if your cough interferes with your daily life and ability to work, or if it comes with any of these other symptoms:

  • Trouble breathing
  • Chest pain
  • Ongoing heartburn
  • Coughing up blood
  • Fever or night sweats
  • Trouble sleeping