It is not unusual to cough up phlegm with a common cold. However, it can also be a sign of a different, sometimes serious, underlying condition such as stomach acid reflux, lung disease, or heart disease.
This article discusses the possible causes of coughing up phlegm and how to treat them. It also explains what different colors of phlegm might indicate and when a person should contact a doctor.
Cough and excess mucus production are common symptoms of upper respiratory tract infections. These illnesses will typically also cause:
Lower respiratory tract infections, which include bronchitis and pneumonia, are more serious. They may produce longer-lasting symptoms.
Other possible causes of coughing up phlegm include:
Acid reflux, also known as gastroesophageal reflux disease (GERD), is when stomach acid moves up into the esophagus (food pipe). GERD can occur due to dysfunction in the lower esophageal sphincter, a hiatal hernia, or dysfunction in the esophagus. The main symptom of GERD is heartburn, though acid reflux can also cause a cough.
Other symptoms include:
- excess saliva
- sore throat
- difficulty swallowing
- oral hygiene issues
Laryngopharyngeal reflux (LPR) is similar to GERD. However, in people with LPR, stomach acid can move up into the esophagus, the voice box, and even the nasal cavity.
LPR can occur due to dysfunction in the lower esophageal sphincter, esophagus, and upper esophageal sphincter. This
- postnasal drip
- frequent throat clearing
- a cough
- feeling a lump in the throat
- excess mucus
Allergic rhinitis causes similar symptoms to a cold, such as:
- dry cough
- runny nose
Some people with allergies may also develop a postnasal drip, which occurs due to excess mucus production that leaks down the throat. This can cause a person to cough up phlegm.
Learn more about allergies here.
Exposure to certain irritants, such as smoke and other fumes, can irritate the airway. This irritation can cause a cough with excess phlegm.
Learn more about air pollution and its effects on health here.
Some lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD), cause a persistent cough and excess phlegm.
Other symptoms of lung disease include:
Heart failure is a condition in which the heart cannot correctly pump or relax to circulate blood around the body. It causes symptoms such as:
- difficulty breathing
- chronic cough
- production of white or pink phlegm
- swelling of the ankles, legs, feet, and abdomen
- nausea and reduced appetite
- disorientation and confusion
- heart palpitations
The color of phlegm may help to indicate the cause of a cough and excess respiratory mucus production. Phlegm may be clear, cream, white, yellow, green, rust-colored, or red.
Lung diseases not related to infection, such as asthma or emphysema, tend to cause clear phlegm.
However, brown or black phlegm can also occur with lung disease, as well as with smoking. For example, black phlegm may be a sign of pneumoconiosis, which people sometimes refer to as “coal workers’ lung.”
Green phlegm is typically associated with infection. According to the American Lung Association, pneumonia can cause a cough that produces green, yellow, or bloody phlegm.
Pink or rust-colored phlegm that contains blood can indicate the presence of a serious medical issue such as tuberculosis or an abscess.
Lung cancer does not
Lung cancer is a less common cause of coughing up phlegm without feeling ill, and many of its symptoms are similar to those of other conditions, such as a lung infection. However, bloody phlegm can be one of the symptoms. Additional common lung cancer symptoms include:
- chronic cough
- chest pain when laughing, breathing deeply, or coughing
- hoarse voice
- reduced appetite
- trouble breathing
- fatigue and weakness
- chronic and recurring respiratory tract infections
To diagnose the underlying condition causing a person to cough up phlegm, a doctor may ask them about the duration of their symptoms and whether there are any known triggers. They will likely ask about the color or texture of the phlegm.
The doctor will check for allergies or respiratory conditions, such as asthma. If they suspect that GERD is the cause, they may perform an upper GI endoscopy.
Blood tests or chest scans are sometimes necessary to rule out other conditions. A person may also need a sputum test to diagnose the type of lung disease.
Anyone with a persistent cough should contact a doctor for a diagnosis. In many cases, the cause will not be serious, though it might still require treatment.
If a person has a cough that produces blood, it is even more urgent that they contact a doctor, as the underlying cause could be serious.
The treatment for coughing up phlegm depends on its cause.
Management strategies for GERD and LPR include:
- lifestyle changes, such as stopping smoking and avoiding foods that trigger heartburn
- medications, which might include antacids to help relieve heartburn
- surgery, in severe cases
The primary treatment for allergies is to identify and avoid triggers. Other treatments include:
- nasal corticosteroids
Most upper respiratory infections will go away on their own.
Over-the-counter decongestants and other products can help with some symptoms in the meantime.
Infections that affect the lower respiratory tract may require treatment from a doctor, who will most likely prescribe an antibiotic.
It is important that a person finishes the entire course of antibiotics, even if their cough and phlegm go away sooner.
A doctor might recommend the following treatments for COPD:
- pulmonary rehabilitation
- supplemental oxygen
Heart failure is a serious condition that requires immediate medical treatment.
Long-term treatment options include:
- lifestyle changes, such as exercising regularly and eating a balanced, nutritious diet
- medication therapy, such as an angiotensin converting enzyme inhibitor, loop diuretic, or beta-blocker
- implantable devices, such as a defibrillator
- surgery, such as a left ventricular assist device, coronary artery bypass grafting, or angioplasty
What is the difference between phlegm, mucus, and sputum?
Although people often use all three terms interchangeably, there is a slight difference between them. Mucus is a general term referring to the substance produced by mucous membranes anywhere in the body. Phlegm and sputum both refer to mucus produced in the lungs and lower respiratory tract.
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What are some natural remedies for coughing up phlegm?
Treating coughing up phlegm depends on the underlying cause and may require contacting a doctor. However, a person
Most causes of coughing up phlegm are not serious. However, more severe conditions, such as COPD or heart failure, require lifelong treatment.
Coughing up phlegm is typically not a cause for concern. For example, GERD and the common cold are responsible for many cases of coughing up phlegm. However, in some cases, this symptom might indicate an undiagnosed condition.
Most causes are treatable. However, while at-home remedies will be sufficient for some, others will require long-term treatment.