Coughing up mucus may be a sign of a respiratory infection or lung issue. The color of the mucus may help inform what’s going on.

Coughing is a natural reflex. It’s your body’s way of clearing your airways of irritants (such as mucus, allergens, or smoke) and preventing infection.

Coughs are often categorized as dry or productive. A productive cough can bring up mucus from the lungs.

Mucus can be several different colors, such as white, green, and yellow, which can all indicate different issues, such as an infection or health condition. White or clear mucus typically indicates healthy lungs.

It’s important to remember that looking at the color of the mucus you’re coughing up isn’t an effective diagnostic tool on its own. If you’re coughing up mucus and are concerned that you may have an infection, consider speakign with a healthcare professional. They can take a closer look at your symptoms and confirm a diagnosis.

Mucus forms a protective coating to keep irritants and germs away from the delicate and sensitive tissues of your airways. Our nose and sinuses produce an average of about a liter of mucus every day.

The airways of the throat and lungs also produce mucus. And the body makes even more mucus when we’re reacting to an allergy or have a cold or infection.

White mucus may be an indication that you have an irritation or possible infection in your respiratory tract.

If you’re coughing up an increased amount of white mucus, it could be a sign of inflammation caused by a lung condition.

Solid white mucus

When you cough up thick, solid white mucus, it might be a signal that you have a bacterial infection in your airways. This type of an infection could require prescription antibiotics from a doctor.

Foamy white mucus

Mucus that contains bubbles and is foamy is commonly referred to as frothy sputum. Frothy sputum can sometimes be a sign of:

If you’re coughing up frothy sputum, review this and other symptoms with your doctor.

Looking at the color of the mucus you’re coughing up isn’t an effective diagnostic tool on its own. The most effective way of identifying bacterial infections is by testing a sample of the sputum in a laboratory.

But mucus color can play a role in determining what’s going on in your respiratory system.

Clear mucus

If you’re coughing up light-colored or clear mucus, it might indicate that you’re dealing with allergies or that you have a minor infection in your respiratory tract.

Yellow or green mucus

If you’re coughing up yellow or green mucus, it may indicate that you have a respiratory infection.

Your mucus changes color because of defensive enzymes that your immune system is releasing. A green tint comes from an iron-containing enzyme, for example.

Red mucus

If you are coughing up red or bloody mucus, you should seek immediate medical attention. This could be a sign of a serious condition, such as lung cancer or a pulmonary embolism (a blood clot in the lung).

There are a number of steps you can take to clear mucus, such as:

  • Keeping yourself hydrated by drinking plenty of fluids — especially water. If you become dehydrated, your mucus can get thicker, which, in turn, may make your cough worse.
  • Using a humidifier to add moisture to the air and loosen mucus.
  • Taking over-the-counter medications. Examples include:
    • expectorants such as guaifenesin (Mucinex)
    • decongestants such as oxymetazoline nasal spray (Afrin, Sudafed OM)
    • pseudoephedrine (Contac 12-Hour, Dimetapp Decongestant)
    • antitussives such as dextromethorphan (Triaminic Cold and Cough, Robitussin Cough).

You should speak with a healthcare professional if your symptoms are not going away or getting worse.

Producing mucus is one of your body’s methods of protecting your respiratory system. When there is an accumulation of mucus, you tend to cough it up.

Although the cause is often a response to a viral infection or an allergy, coughing up mucus could be an indication of a bacterial infection.

There are a number of simple ways to care for yourself if you’re coughing up mucus. But if the symptoms continue to worsen or stick around, it’s important to speak with a doctor.