Coughing is a symptom of many conditions and illnesses. It’s is your body’s way of responding to an irritant in the respiratory system.
When irritants like dust, allergens, pollution, or smoke enter your airways, specialized sensors send a message to your brain, and your brain is alerted to their presence.
Your brain then sends a message through the spinal cord to the muscles in your chest and abdomen. When these muscles rapidly contract, it pushes a burst of air out through your respiratory system. This burst of air helps push out harmful irritants.
Coughing is an important reflex that can help remove harmful irritants that may sicken you or make it harder to breath. When you’re ill, a cough can also move mucus and other secretions out of your body to help you clear your airways, breathe easier, and heal faster.
Coughing is often worse at night because mucus collects at the back of your throat when you lie down, further triggering your cough reflex.
Sometimes, the characteristics of your cough can be an indication of its cause.
A wet cough, also known as a productive cough, is any cough that produces mucus (phlegm). It may feel like you have something stuck in your chest or the back of your throat. Sometimes a wet cough will bring mucus into your mouth.
A wet cough indicates that your body is producing more mucus than normal.
Wet coughs most often result from infections by microorganisms such as bacteria or viruses, like those that cause a cold or flu.
Your entire respiratory system is lined with mucus membranes. Mucus performs many beneficial functions in your body, like keeping your airways moist and protecting your lungs from irritants.
When you’re fighting off an infection like the flu, however, your body produces more mucus than usual. It does this to help trap and expel the organisms causing infection. Coughing helps you get rid of all the excess mucus that gets stuck in your lungs and chest.
There are other reasons why your body may produce more mucus than usual, causing you to develop a wet cough. If your wet cough has been going on for more than a few weeks, it could be caused by:
- Bronchitis. Bronchitis is inflammation in the bronchial tubes, the tubes that carry air into your lungs. Acute bronchitis is typically brought on by a variety of viruses. Chronic bronchitis is an ongoing condition, often caused by smoking.
- Pneumonia. Pneumonia is an infection in your lungs that is caused by bacteria, viruses, or fungi. It’s a condition that ranges in severity from mild to life-threatening.
- COPD. Chronic obstructive pulmonary disease (COPD) is a group of conditions that damage both your lungs and the tubes that bring air into your lungs. Smoking is the number one cause of COPD.
- Cystic fibrosis. Cystic fibrosis is a genetic condition of the respiratory system that’s usually diagnosed during early childhood. It causes the production of thick, sticky mucus in the lungs and other organs. All 50 states screen infants for cystic fibrosis at the time of birth.
- Asthma. Although people with asthma are more likely to have a dry cough, a small subset of people produce ongoing excess mucus and experience a chronic wet cough.
- Whooping cough presents in violent attacks of uncontrollable coughing. Children make a “whoop” sound as they gasp for air.
- Cough in children is sometimes caused by inhaling a foreign body, cigarette smoke, or other environmental irritants.
- Pneumonia is an infection in the lungs that can be dangerous in newborns and young children.
To diagnose your cough, your doctor will first need to know how long it’s been going on and how severe the symptoms are.
Most coughs can be diagnosed with a simple physical exam. If your cough is long-lasting or severe, or you have other symptoms like fever, weight loss, and fatigue, your doctor may want to order additional tests.
Additional testing may include:
- chest X-rays
- lung function tests
- sputum analysis, a microscopic look at phlegm
- pulse oximetry, which measures the amount of oxygen in your blood
- arterial blood gas, which tests a blood sample from an artery to show the amount of oxygen and carbon dioxide in your blood, along with your blood chemistry
Treatments for a wet cough depend on what’s causing it. For the majority of wet coughs caused by a virus such as a cold or flu, treatment is unnecessary. Viruses must simply run their course. Bacterial causes require antibiotics.
If you or your child is having trouble sleeping, you may want to use something to help lessen phlegm and cough. Research has shown that 1/2 teaspoon of honey before bedtime in children is a safe method to try. Keep in mind that raw honey isn’t suitable for children under 12 months old due to the risk of botulism.
According to the American Academy of Pediatrics, children under the age of 4 shouldn’t be given over-the-counter (OTC) cough and cold medications.
Other possible treatments for wet cough can include:
- cool mist vaporizer
- acetaminophen (Tylenol) or ibuprofen (Advil) for body aches and chest discomfort from cough
- OTC cough medicines (for older children and adults)
- prescription cough medicines (with or without codeine — codeine isn’t recommended in cough medicines for children under age 12)
- steroids for coughs related to asthma
- allergy medications
- antibiotics for bacterial infections
- moist air (delivered by humidifier or steam)
A dry, hacking cough is a cough that doesn’t produce mucus. Dry coughs can be painful and difficult to control. They happen when your respiratory system is inflamed or irritated, but not producing excess mucus.
Dry coughs are common in the weeks following a respiratory infection. Once the excess mucus is cleared, a dry cough can linger for weeks or even months.
Other possible causes of dry cough include:
- sore throat
- gastroesophageal reflux disease (GERD)
- medications (particularly ACE inhibitors)
- exposure to irritants (air pollution, dust, smoke)
Consult a doctor if your cough has been going on for more than two weeks. You may need immediate medical attention if you’re having trouble breathing or coughing up blood, or notice a bluish skin tone. Mucus with a foul smell can also be a sign of a more serious infection.
Call the doctor immediately if your child:
- is younger than 3 months of age and has a fever 100.4ºF (38ºC) degrees or higher
- is younger than 2 years of age and has a fever over 100.4ºF (38ºC) for more than a day
- is over 2 years of age and has a fever of 100.4ºF (38ºC) or higher for more than three days
- has a fever of 104ºF (40ºC) or higher
- has wheezing without a history of asthma
- is crying and can’t be comforted
- is difficult to wake
- has a seizure
- has a fever and rash
Wet coughs are most often caused by minor infections. If your cough has been going on for two weeks or more, see your doctor. More serious causes are possible.
Treatment for your cough will depend on the cause. Since most coughs are caused by viruses, they will go away on their own with time.