Cough

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 stomach area to push air out of your lungs to force out the irritant.

A cough once in a while is common and healthy. A cough that lasts for several weeks or one that brings up discolored or bloody mucus may be a sign of a condition that needs medical attention.

At times, coughing can be very forceful. Strong coughing that lasts a long time can irritate the lungs and cause even more coughing. It also is very tiring and can cause sleeplessness, dizziness or fainting; headaches; leaking of urine; vomiting; and even broken ribs.

While a cough once in a while is common, a cough that lasts for several weeks or one that brings up discolored or bloody mucus may be a sign of a medical condition. A cough is called "acute" if it lasts less than three weeks. It's called "chronic" if it lasts longer than eight weeks in adults or longer than four weeks in children.

Infections or flares of chronic lung conditions cause most acute coughs. Most chronic coughs are related to underlying lung, heart or sinus conditions.

Common infectious causes of acute cough

Common infectious causes of acute cough include:

• Acute sinusitis
• Bronchiolitis (especially in young children)
• Bronchitis
• Common cold
• Croup (especially in young children)
• Influenza (flu)
• Laryngitis
• Pneumonia
• Respiratory syncytial virus (RSV)
• Whooping cough

Some infections, particularly whooping cough, may cause so much inflammation that the cough can last for many weeks or even months after the infection itself has cleared up.

Common lung causes of chronic cough

Common lung causes of chronic cough include:

• Asthma (most common in children)
• Bronchiectasis, which leads to a buildup of mucus that can be streaked with blood and raise the risk of infection
• Chronic bronchitis
• COPD
• Cystic fibrosis
• Emphysema
• Lung cancer
• Pulmonary embolism
• Sarcoidosis (a condition in which tiny collections of inflammatory cells can form in any part of the body)
• Tuberculosis

Other causes of cough

Other causes of cough include:

• Allergies
• Choking: First aid (especially in children)
• Chronic sinusitis
• Gastroesophageal reflux disease (GERD)
• Heart failure
• Inhaling an irritant, such as smoke, dust, chemicals or a foreign body
• Medicines called angiotensin-converting enzyme inhibitors, also known as ACE inhibitors
• Neuromuscular diseases that weaken the coordination of upper airway and swallowing muscles
• Postnasal drip, which means fluid from the nose runs down the back of the throat

Call your healthcare professional if your cough — or your child's cough — doesn't go away after a few weeks or if it also involves:

• Coughing up thick, greenish-yellow phlegm.
• Wheezing.
• A fever.
• Shortness of breath.
• Fainting.
• Ankle swelling or weight loss.

Seek emergency care if you or your child is:

• Choking or vomiting.
• Having trouble breathing or swallowing.
• Coughing up bloody or pink-tinged phlegm.
• Having chest pain.

Self-care measures

Cough medicines usually are used only when a cough is a new condition, causes a lot of discomfort, disrupts your sleep and is not linked with any of the worrisome symptoms listed above. If you use cough medicine, be sure to follow the dosing instructions.

Cough and cold medicines that you buy off the shelf aim to treat the symptoms of coughs and colds, not the underlying disease. Research suggests that these medicines don't work any better than taking no medicine at all. More importantly, these medicines are not recommended for children because of risks of serious side effects, including fatal overdoses in children under 2 years old.

Don't use medicines that you can buy without a prescription, except for fever reducers and pain relievers, to treat coughs and colds in children younger than 6 years old. Also, don't use these medicines for children under 12 years old. Ask your healthcare professional for guidance.

To ease your cough, try these tips:

• Suck on cough drops or hard candies. They may ease a dry cough and soothe an irritated throat. But don't give them to a child under age 6 because of the risk of choking.
• Think about taking honey. A teaspoon of honey may help loosen a cough. Don't give honey to children younger than 1 year old because honey can contain bacteria harmful to babies.
• Keep the air moist. Use a cool mist humidifier 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.
• Stay away from tobacco smoke. Smoking or breathing secondhand smoke can make your cough worse.