Yellow nasal discharge – what does the colour of nasal secretions mean?

A runny nose is a symptom that can have many causes and does not always indicate an infection. It most often occurs during a cold, i.e. a viral infection of the upper respiratory tract. A yellow, sometimes yellow-green runny nose is usually not a sign of a ‘severe’ infection, nor is it automatic proof of a bacterial infection. A runny nose with a cold usually goes away on its own, so in addition to taking care of your nutrition and avoiding irritants, it is also worth being patient.

1. Common causes of a runny nose
2. The source of yellow nasal discharge
3. Combating a runny nose

Common causes of a runny nose

In the case of an infectious runny nose, the discharge is usually watery and profuse at first, and after a few days it becomes thicker and may turn yellowish or greenish in colour. This is accompanied by sneezing, nasal congestion, a scratchy throat and general weakness, and the symptoms usually resolve spontaneously within one to two weeks.

The second very common cause is allergic rhinitis. It is usually watery, clear and recurrent, often accompanied by sneezing, itchy nose and eyes, and watery eyes. Symptoms appear after contact with an allergen, such as pollen, house dust mites or animal hair, and can persist for weeks or months if exposure continues.

Some people experience a runny nose without infection or allergies. This is known as vasomotor rhinitis, in which the nasal mucosa reacts excessively to stimuli such as cold air, sudden changes in temperature, dry or polluted air, strong smells, alcohol or spicy foods. The discharge is then watery, and the symptoms may appear suddenly and disappear after the stimulus is removed.

"The right choice of dietary supplements can support our immune system. The most commonly recommended supplements include: vitamin C, vitamin D3, garlic, probiotic bacteria, omega-3 fatty acids." Tomasz Maciołek - Physiotherapist and Trainer

A runny nose may also be associated with sinusitis, especially when accompanied by facial pressure, headache, impaired sense of smell and discharge running down the back of the throat. In some people, chronic rhinitis is due to anatomical causes, such as a deviated septum or polyps. It is also worth remembering about drug-induced rhinitis, which develops with prolonged use of nasal decongestant drops, and the impact of hormonal changes, for example during pregnancy.

Factors causing certain types of rhinitis

The source of yellow nasal discharge

In many cases, during an infection or irritation of the nasal mucosa, the consistency of the secretion changes. At first, the runny nose is watery, and after a few days it becomes thicker and stickier. This is because there is less water in the mucus and more proteins and cells involved in the inflammatory response. These are what can give it a yellowish or greenish colour, even if the symptoms are caused by a simple viral infection.

Does the colour matter?

The colour of nasal discharge is of little diagnostic significance when considered in isolation from other symptoms. A yellow runny nose can occur both during a cold and during recovery, when the body is gradually reducing the inflammation. It often worsens in the morning, after a night spent in dry air, breathing through the mouth or with insufficient hydration. The mere fact that the discharge is thick and has a more intense colour does not mean that antibiotic treatment is necessary.

What to look for?

The duration and course of the symptoms are more important. If a runny nose, nasal congestion, headache or pressure in the sinus area persist for more than about 10 days without significant improvement, if after a few days of slight improvement there is a recurrence of symptoms, or if there is a high fever and severe facial pain from the outset, then bacterial sinusitis is more likely to be considered.

Combating a runny nose

Rinsing the nose with saline solution or sea water can be helpful in combating a runny nose. These fluids thin the secretions, facilitate their removal and reduce the feeling of congestion. It is important that the solution is sterile or prepared from boiled (and cooled) water, and that too much pressure is not applied. Hot steam inhalations do not have a lasting effect on a runny nose and can easily cause burns.

"Daily consumption of probiotic-rich foods or supplements helps the body to better cope with infections by regulating the immune response and strengthening the body's natural protective barrier." Łukasz Domeracki - MSc in Food Technology

Analyses of human studies suggest that zinc lozenges taken early after the onset of infection may shorten the duration of a cold and thus a runny nose. Vitamin C taken regularly or from the onset of infection also usually results in a measurable reduction in symptom severity. In studies on herbal products, some preparations containing purple coneflower were associated with more effective prevention and faster improvement, as were selected probiotics.

Sources:

• van den Broek, M. F., Gudden, C., Kluijfhout, W. P., Stam-Slob, M. C., Aarts, M. C., Kaper, N. M., & van der Heijden, G. J. (2014). No evidence for distinguishing bacterial from viral acute rhinosinusitis using symptom duration and purulent rhinorrhea: a systematic review of the evidence base. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery, 150(4), 533–537. https://doi.org/10.1177/0194599814522595
• Kenealy, T., & Arroll, B. (2025). Antibiotics for the common cold and acute purulent rhinitis. The Cochrane database of systematic reviews, 11(11), CD000247. https://doi.org/10.1002/14651858.CD000247.pub4
• King, D., Mitchell, B., Williams, C. P., & Spurling, G. K. (2015). Saline nasal irrigation for acute upper respiratory tract infections. The Cochrane database of systematic reviews, 2015(4), CD006821. https://doi.org/10.1002/14651858.CD006821.pub3
• Kanjanawasee, D., Seresirikachorn, K., Chitsuthipakorn, W., & Snidvongs, K. (2018). Hypertonic Saline Versus Isotonic Saline Nasal Irrigation: Systematic Review and Meta-analysis. American journal of rhinology & allergy, 32(4), 269–279. https://doi.org/10.1177/1945892418773566