Coughing Up White Mucus

If you are coughing up white mucus, you probably want to know what it means for your health. While the color of your mucus might suggest what is causing it, that's not always the case.

Your doctor might ask you about the color of your mucus, but they usually can't diagnose you based on mucus color alone. They will also want to know about the consistency (thickness) and other characteristics of the mucus that you are coughing up.

Causes of White Mucus - Illustration by Michela Buttignol

Verywell / Michela Buttignol

Here's what we know about coughing up white-colored mucus.

Why Do We Cough?

Coughing is a protective reflex that keeps unwanted substances out of your airways and lungs. If you can't cough, you are at risk of aspiration and other respiratory problems.

While the occasional cough is not necessarily a sign of a problem, some conditions like respiratory infections or allergies can cause you to cough more often as your body makes an effort to remove excess mucus.

What Is Mucus?

Mucus is a substance that is found in several parts of the body, including the respiratory tract. The mucus that specifically comes from the respiratory tract is often called sputum.

Mucus is secreted by glands and is made up of water, salt, epithelial cells, and dead leukocytes (white blood cells).

The function of mucus is to lubricate and protect delicate structures. It can trap small particles (such as germs and dust), making it easier for them to be safely removed from the body.

Coughing Up White Mucus

The color of your mucus alone is not a good diagnostic tool. A doctor may look at a sample of sputum to see if it has white blood cells or bacteria (Gram stain) in it.

Studies have shown that sputum infected with bacteria tends to be green, yellow, or another color; it's rarely cream-colored, white, or clear.

If you have white mucus, it means there are white blood cells in it. The cause could be a virus, bacteria, or another pathogen. It could also indicate a condition like pneumonia.

Conditions that may cause white mucus are:

Solid White Mucus

Solid, thick mucus of any color tends to be associated with specific causes. For example, thick mucus can occur from dehydration or because swollen, inflamed tissues are slowing the ability of mucus to flow through the respiratory passageways.

If the mucus is from these causes, increasing your fluid intake and using a cool-mist humidifier next to your bed at night can help thin out your mucus and make it easier to clear.

Foamy White Mucus

White mucus can also appear foamy or frothy if there are large amounts of air bubbles in it. A small amount of foamy white mucus is not usually a concern; however, a larger amount of foamy mucus or mucus that is blood-tinged or pink can indicate a serious illness.

Foamy white mucus can occur in the following conditions:

Other Colors of Mucus


Normal, healthy sputum is clear because it contains mostly water. Some respiratory conditions can produce clear sputum with changes in the consistency or amount, especially early in the course of the illness.

Yellow or Green

Yellow or green sputum is called "purulent" because it contains pus. The color is created by a type of white blood cell called neutrophils, which have a green hue.

Yellow sputum typically contains small amounts of neutrophils, while green sputum has higher amounts of these immune cells.

While a doctor cannot diagnose a bacterial infection based on the color of mucus alone, studies have found that green or yellow sputum is more likely than other colors of mucus to be caused by bacterial infections.


Mucus may appear brown if it contains old blood or if you have inhaled a significant amount of dirt (for example, you were caught in a dust storm). If the old blood came from the lungs, it can be a sign of hemoptysis.

You might occasionally see brown mucus if you have had a bloody nose recently, in which case the mucus actually originated in your nasal passageways.


Mucus may appear red if there is fresh blood in it. When the blood is coming from the lungs (as opposed to the nasal passageways), it is called hemoptysis.

Hemoptysis can be a serious condition. It is generally caused by lung cancer, bronchitis, or pneumonia. In rare cases, it can be caused by tuberculosis.

When to Call a Doctor

If you are coughing up mucus that appears blood-tinged, call your doctor. If you cannot tell how much mucus you are coughing up, try spitting into a cup that you can measure and report this information to your healthcare provider.

You might be able to have your doctor assess your mucus production at an office visit; however, in some cases, they might want you to go to the emergency room for more urgent care.


Black sputum can be caused by inhaling something black, such as coal dust. It can also be caused by an infection (typically those that are caused by a fungus or tuberculosis) or death of lung tissue (ischemic necrosis).

Treating Wet Coughs

A wet cough is also called a productive cough. The goal of treating a cough that is producing mucus is addressing what is causing it rather than only easing the symptom of coughing.


For example, if your cough is being caused by GERD, medications called proton pump inhibitors (PPIs) can be helpful.

You might also try elevating your upper body (to prevent reflux of stomach acid into the esophagus).

Losing weight and changing your diet can also offer relief. Severe cases of GERD might require surgical intervention.

Viral Infections

Unlike illnesses that are caused by bacteria, viral respiratory infections cannot be treated with antibiotics. Instead, treatment is focused on helping your immune system fight the infection.

Things you can do to help your body fight a viral infection that is causing a cough include getting plenty of rest, nourishing your body, and staying hydrated.

Increasing your fluid intake, using a cool-mist humidifier, and using saline nasal sprays can help thin the mucus and make it easier to clear. Lozenges (cough drops) can also help relieve symptoms.

Research is mixed on how helpful and safe over-the-counter (OTC) cough medicines are. Ask your doctor or pharmacist before using these products for a cough.

If you have bronchitis, asthma, or COPD, your doctor might prescribe inhaled respiratory medications.


Coughing up white mucus has several possible causes. Your doctor won't be able to figure out what is causing the mucus just by looking at it, however. In some cases, they might need to test a sample of the mucus to see if there are specific pathogens in it.

If your cough is caused by a bacterial infection, you might need antibiotics. If it's caused by a virus, the treatment will be focused on helping your immune system fight off the infection and easing your symptoms.

Other causes of white mucus, like chronic health conditions, sometimes benefit from lifestyle changes, using a humidifier, or taking an inhaled respiratory medication.

If you are concerned about your coughing or mucus production, call your doctor. While occasional white mucus is likely not a reason to worry, coughing up a lot of white mucus, coughing up mucus that has blood in it, or coughing up mucus when you also have other symptoms can be signs of a more serious condition.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Lung Association. Learn About Cough.

  2. Encyclopedia Brittanica. Mucus Secretion.

  3. MedlinePlus. Sputum Culture.

  4. Cedars Sinai. Bronchitis.

  5. Cleveland Clinic. What the Color of Your Snot Really Means.

  6. Cleveland Clinic. Coughing Up Blood (Hemoptysis).

  7. National Institute of Diabetes and Digestive and Kidney Diseases. Treatment for GER and GERD.

  8. Nationwide Children's. Upper Respiratory Infections (Colds).

By Kristin Hayes, RN
Kristin Hayes, RN, is a registered nurse specializing in ear, nose, and throat disorders for both adults and children.