Coughing is a reflex that occurs in response to irritation in the throat or lungs. It is the body’s way of removing irritants such as fluid and phlegm.

A wet cough occurs when fluid in the airways triggers the coughing reflex. Another name for a wet cough is a productive cough, since it produces phlegm.

A wet cough can occur for a variety of reasons. Some potential causes include:

• respiratory infections
• chronic lung conditions
• a heart condition

Sometimes, a wet cough is accompanied by other symptoms, such as:

• shortness of breath
• wheezing
• bubbling, popping, or rattling sounds, called “crackles”
• continuous, low-pitched, snore-like sounds, called “rhonchi”
• pink tinged phlegm

These symptoms can provide a clue as to what is causing the wet cough.

Various disease processes affect the lungs in different ways. A wet cough indicates that there is fluid in the airways. With a dry cough, however, there is little to no fluid in the airways. Therefore, a dry cough does not produce phlegm.

Some conditions may produce either a wet cough or a dry cough. Other conditions may produce mainly one or mainly the other, but with both potentially present.

Causes of a wet cough

Some typical causes of a wet cough include:

A respiratory infection

A wet cough often occurs as a result of a respiratory infection. Various types of respiratory infection can lead to an increase in mucus, including:

Other potential symptoms of a respiratory infection include:

Bronchiectasis

The bronchial tubes carry air in and out of the lungs. Bronchiectasis is a condition in which the surface tissue of the bronchial tubes becomes thick, floppy, and scarred, with a widening of the tube diameter as a result of chronic inflammation.

This results in excess mucus production, which can trigger a wet cough. Excess mucus production, leading to a buildup within the bronchial tubes, also increases the risk of a lung infection.

Some other potential symptoms of bronchiectasis include:

• wheezing
• breathlessness
• fatigue
• coughing up blood or blood stained phlegm
• chest pain
• joint pain
• clubbing of the fingertips

Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an umbrella term for a group of chronic and progressive lung conditions. Some of these include:

Some forms of COPD cause damage to the tiny air sacs within the lungs, while others affect the bronchial tubes, the bronchioles, or both.

Some symptoms of COPD include:

• a wet cough
• wheezing
• shortness of breath
• tightness in the chest

Congestive heart failure

Congestive heart failure (CHF) occurs when the heart has difficulty pumping blood throughout the body. When this ineffective pumping occurs on the left side of the heart, it causes fluid to leak into the air sacs within the lungs. The result is a wet cough, crackles, and wheezing.

According to the American Heart Association (AHA), CHF may produce pink tinged mucus. Some additional symptoms may include:

• shortness of breath
• fatigue
• swelling of the legs or feet, due to right sided heart failure causing poor circulation

Causes of a dry cough

A dry cough differs from a wet cough in that it does not produce any fluid or mucus. It generally develops in response to irritation or inflammation of the airways.

Some common causes of a dry cough include:

• gastroesophageal reflux disease
• asthma
• pulmonary fibrosis
• certain medications

People with a persistent wet cough may seek treatments to suppress it. However, suppressing a wet cough can lead to a buildup of mucus in the air passages of the lungs. This can lead to further complications, such as breathing difficulties and infection.

Instead of suppressing it, wet cough treatments typically aim to improve cough efficiency, thereby helping people clear the airways.

Other treatments aim to clear phlegm and associated irritation in the back of the throat.

If the cough is due to an underlying medical condition, a doctor will prescribe specific treatments for that condition.

Treatments to improve cough efficiency and clear phlegm

Some of the treatments below help improve cough efficiency. Others decrease mucus in the back of the throat, thereby reducing the need to cough.

Expectorants and mucolytics

Expectorants and mucolytics are medications that thin the mucus and make it less sticky. This makes it easier for people to cough it up.

These medications work best for people who have a wet cough but are having difficulty getting the phlegm up.

Airway clearance devices

Airway clearance devices, such as the oscillating positive expiratory pressure (PEP) device, use pressure and vibration to help shift phlegm from the airways during exhalation. This helps improve cough efficiency.

A 2014 review investigated the efficacy of PEP therapy in the treatment of stable bronchiectasis. The review included seven studies involving a total of 146 participants. The researchers found that PEP therapy improved cough effectiveness and sputum expectoration when compared with no treatment.

Gargling with salt water

Gargling with salt water is an easy home remedy that may help alleviate a wet cough. The salt water may decrease mucus in the back of the throat, thereby reducing the need to cough.

A range of different salt water recipes are available. Most, including that of the American Dental Association, recommend mixing half a teaspoon of salt with 8 ounces of warm water. People should consider gargling this a few times per day to reduce phlegm.

Specific treatments

The treatment options for a wet cough also depend partly on the cause. Some more specific treatments include:

Antibiotics

Antibiotics are helpful for a wet cough that occurs due to a bacterial infection.

One 2017 review found that taking appropriate antibiotics helps improve the resolution of a chronic wet cough among children with bacterial bronchitis.

Medications to treat CHF

People who experience a wet cough due to CHF may receive drugs called diuretics, which help relieve fluid retention. This, in turn, can reduce the amount of fluid in the lungs, which can help alleviate a wet cough.

People who have CHF may also receive drugs to:

In some cases, a wet cough may signal a serious underlying health condition, such as a lung or heart disease. If a person is in any doubt as to the cause of a wet cough, they should make an appointment to see their doctor.

People should see a doctor as soon as possible if they experience any of the following symptoms alongside a cough:

• foul-smelling phlegm
• green, yellow, or pink tinged phlegm
• coughing up blood
• swelling in the legs, feet, or ankles
• a wet cough that lasts more than a few days
• significant fever or chills

People who experience the following symptoms should seek emergency medical attention:

• bluish skin or nails
• labored breathing
• confusion or loss of consciousness
• chest pain

A wet cough occurs as a result of excess fluid or mucus in the airways. A range of conditions can cause a wet cough, including respiratory infections, chronic lung conditions, and CHF.

Once a doctor has diagnosed the underlying cause of a wet cough, a person can begin appropriate treatment.

The treatment will depend partly on the cause of the wet cough. Medications such as mucolytics and expectorants can help remove mucus from the lungs. Antibiotics can help treat bacterial respiratory infections, while specific CHF medications will be necessary to treat the symptoms of heart failure.

People should see a doctor if they are in any doubt as to the cause of their wet cough.