What Do the Different Colors of Mucus Mean?

The sinuses are protected by mucus. When the viscosity and colors of the mucus change, you may need to see your doctor.
What Do the Different Colors of Mucus Mean?

Last update: 18 July, 2022

Mucus protects the respiratory system from aggressive external factors, such as viruses, pollen, smoke, and other substances. The colors of mucus may vary without any serious process occurring in your body. However, it’s important to be aware of what the color changes may mean.

Respiratory viral infections are the most frequent affections in children, as highlighted by the magazine Pediatría Integral. Likewise, patients with medical conditions related to the respiratory tract have to watch out for bacterial alterations that show themselves through nasal secretions.

Among these conditions, the Practical Primary Care bulletin includes acute bronchitis, pneumonia, and acute exacerbations of chronic obstructive pulmonary disease (COPD).

What’s the function of mucus?

Mucus is a mix of water, immunoglobulins, mucopolysaccharides, glycoproteins, and lipids, which forms to create an immune barrier to protect us against pathogens or allergens. It’s produced by the epithelial cells of the nose, mouth, sinuses, pharynx, bronchioles, and bronchi.

The job of mucus is to filter, humidify and warm the air breathed through the nostrils. The mucus moisturizes the respiratory tract to take away the dryness.

Apart from the colors of the mucus, the texture says a lot about your health. This characteristic is marked by wateriness, and how it flows.

The colors of mucus.
It’s common for children to have continual runny noses. This is because they’re being exposed to many pathogens for the first time.

Excess mucus: stuffy nose

Occasionally, people suffer from nasal congestion, which is caused by swollen blood vessels and tissues with excess fluid, as Mayo Clinic explains. However, a publication in Clinical Otolaryngology concludes that the blockage serves as a defense mechanism against respiratory viruses.

To soothe the stuffy feeling, there are several recommendations:

  • Blow your nose as much as you need to; if you prefer, tilt your head to one side.
  • Avoid irritants and pollen.
  • If you work with dust, use a mask.
  • Drink plenty of water.
  • Spray saline solution into the nostrils. For babies, the Spanish Association of Paediatrics suggests nasal washes.

You may be interested in: Seven Remedies to Relieve Nasal Congestion

Why are the colors of mucus different?

The consistency and colors of mucus give clues as to what’s going on in your respiratory system. While they don’t provide a definitive diagnosis, checking the tissue after blowing your nose helps specialists make treatment decisions.

Here’s what each color represents.

Clear mucus

Colorless mucus is assumed to be normal. It’s also considered to be a sign of a cold or allergic rhinitis. It isn’t dangerous. What is irregular is an excessively runny nose, which may seep into the throat.

When the discharge is allergic, the symptomatology you experience is based on sneezing, watery eyes, coughing, fatigue, an itchy nose, and a sore throat. Although not always, pregnant women may experience clear nasal discharge due to mucosal inflammation and hormonal changes.

Yellow mucus

Viral infections manifest as yellowish mucus. The color is due to the defense wielded by the cells to fight the disease.

The discomfort usually lasts up to 2 weeks, during which time the color darkens a little. This means that the body has done its job of killing the germs.

White mucus

A whitish mucus denotes congestion, inflammation, or swelling in the nose. As the nostrils become blocked, the mucus thickens and becomes cloudy.

This occurs as a result of colds or infections that show symptoms up to 3 days after exposure to the causative agent. The body feels unwell and the patient experiences a sore throat, sneezing, headache, mild muscle pain, cough, and a fever.

Green mucus

Bacterial sinus infections secrete thick green mucus. This kind of discharge is called mucopurulent. The mucus contains white blood cells responsible for fighting bacteria and viruses, and, in the process, they generate iron-containing enzymes, which results in the green appearance of the discharge.

Greenish nasal discharge may be from chronic sinusitis. Along with other signs, such as fever, chest side pains, and yellow coughing up phlegm, green mucus would be associated with pneumonia.

Discover more in this article: What Is Nasal Mucus and What Does It Do?

Brown mucus

Three possibilities surround the meaning of brown mucus. This coloration can occur from inhaling powder, tobacco, or something of a reddish-brown color. It may also be old blood seeking to leave the body. A final possibility is a respiratory infection, if it’s accompanied by dyspnea, high fever, malaise, and cough.

Red color in mucus

Pink or bloody mucus is due to factors such as blowing your nose a lot or suffering a blow to this part of the body. Catarrhal conditions, nosebleeds, and an irritation of the pharynx cause bloody mucus. The same happens with more serious pathologies, such as tuberculosis or lung cancer.

It’s important to go to the doctor if you have difficulty breathing, bleed more than a spoonful of blood, or if the bleeding doesn’t stop after half an hour.

A nosebleed.
Blood in the mucus should be evaluated carefully to determine if it’s due to a serious pathology.

Black mucus

Nasal fungal infections are revealed through black mucus. Smokers and drug users, mine workers, or those who inhale smoke in highly polluted areas are prone to dark secretions.

When to see a doctor?

Having a cold for more than 10 days is a sign that you should go to see a doctor. If it’s a bacterial infection, the discomfort will worsen during that time. Keep an eye out for fever, headaches, eye pain, vomiting, or sensitivity to light.

If mucus increases or mucus colors change over the course of the day, don’t delay going to see a doctor. It’s preferable to rule out a simple process rather than worsen a serious condition.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.



This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.