Medically reviewed on Jan 11, 2018
A cough is your body's way of responding when something irritates your throat or airways. An irritant stimulates nerves that send a message to your brain. The brain then tells muscles in your chest and abdomen to push air out of your lungs to force out the irritant.
An occasional cough is normal and healthy. A cough that persists for several weeks or one that brings up discolored or bloody mucus may indicate a condition that needs medical attention.
At times, coughing can be very forceful — the velocity of air from a vigorous cough can approach 500 miles an hour. Prolonged, vigorous coughing is exhausting and can cause sleeplessness, headaches, urinary incontinence and even broken ribs.
While an occasional cough is normal, a cough that persists may be a sign of a medical problem.
A cough is considered "acute" if it lasts less than three weeks. It is considered "chronic" if it lasts longer than eight weeks (four weeks in children).
Some causes of coughs include:
Common causes — acute
- Common cold
- Influenza (flu)
- Inhaling an irritant
- Whooping cough
Common causes — chronic
- Asthma (most common in children)
- Gastroesophageal reflux disease (GERD)
- Postnasal drip
- Acute sinusitis (sinus infection)
- Bronchiectasis (a chronic lung condition in which abnormal widening of bronchial tubes inhibits mucus clearing)
- Bronchiolitis (especially in young children)
- Choking: First aid (especially in children)
- Chronic sinusitis
- COPD (chronic obstructive pulmonary disease)
- Croup (especially in young children)
- Cystic fibrosis
- Heart failure
- Lung cancer
- Medications called angiotensin-converting enzyme (ACE) inhibitors
- Neuromuscular diseases, such as parkinsonism, which weaken the coordination of upper airway and swallowing muscles
- Respiratory syncytial virus (RSV) — especially in young children
When to see a doctor
Call your doctor if your cough doesn't go away after several weeks or if you or your child is:
- Coughing up thick, greenish-yellow phlegm
- Experiencing a fever more than 100 F (38 C)
- Experiencing shortness of breath
Seek emergency care if you or your child is:
- Having difficulty breathing or swallowing
- Coughing up bloody or pink-tinged phlegm
Cough medicines usually are used only when the cause of the cough is unknown and the cough causes a lot of discomfort. If you use cough medicine, be sure to follow the dosing instructions.
Don't give children under age 4 over-the-counter cough medicine without first checking with your child's doctor.
To ease your cough, try these tips:
- Suck cough drops or hard candies. They may ease a dry cough and soothe an irritated throat. Don't give them to a child under age 6, however, because of the risk of choking.
- Take honey. A teaspoon of honey can help loosen a cough. Don't give to children younger than 1 year old.
- Moisturize the air. Use a vaporizer or take a steamy shower.
- Drink fluids. Liquid helps thin the mucus in your throat. Warm liquids, such as broth tea or lemon juice, can soothe your throat.
- Avoid tobacco smoke. Smoking or breathing secondhand smoke can make your cough worse.