Asthma does not usually cause a runny nose by itself. However, asthma and a runny nose can happen together, often because of allergies such as pollen or dust mites, or because of a respiratory infection. Allergies can affect both the nose and lungs, while asthma mainly causes breathing symptoms such as wheezing, coughing, chest tightness, and shortness of breath. The reason for nasal symptoms depends on the pattern.
Does asthma directly cause a runny nose?
Asthma primarily affects the airways in the lungs, causing inflammation and narrowing that can make breathing difficult. A runny nose, by contrast, usually occurs when the lining inside the nose becomes irritated or inflamed and produces excess mucus. According to the NHS, the main symptoms of asthma include wheezing, coughing, shortness of breath, and chest tightness. A runny nose is not considered one of its main symptoms.
Although asthma itself is not usually the direct cause of nasal discharge, the two problems can occur at the same time. This is especially relevant when allergies or respiratory infections affect the upper and lower parts of the respiratory system.
Why do asthma and a runny nose occur together?
Allergies can affect both the nose and lungs
Allergies are an important reason why someone may experience a runny nose alongside asthma symptoms. When the immune system reacts to substances such as pollen, dust mites, mold, or pet dander, it can produce symptoms in the nose and, in susceptible people, affect the airways. The Mayo Clinic explains that the same allergic response can cause nasal symptoms and asthma symptoms in some people.
Allergic rhinitis, commonly called hay fever, is inflammation of the nasal lining caused by an allergic reaction. It may occur seasonally, such as during periods of high pollen exposure, or throughout the year in response to indoor allergens.
The American Academy of Allergy, Asthma & Immunology notes that allergic rhinitis can contribute to problems associated with asthma and may worsen asthma symptoms in people who have both conditions.
Respiratory infections can cause nasal symptoms and trigger asthma symptoms
A common cold or another respiratory infection can lead to a runny nose, sneezing, and nasal congestion. In someone who has asthma, the same infection may also trigger increased coughing, wheezing, or breathlessness. In this situation, the infection can explain why nasal and breathing symptoms develop around the same time, rather than asthma directly causing the runny nose.
The Centers for Disease Control and Prevention (CDC) explains that respiratory infections, including influenza, COVID-19, and respiratory syncytial virus (RSV), can complicate asthma and lead to asthma attacks. A new runny nose accompanied by other signs of illness should therefore be considered in the context of possible infection.
Nonallergic nasal irritation may also be responsible
Not every runny nose is caused by an allergy. Nonallergic rhinitis can cause persistent or recurring nasal symptoms when the lining of the nose reacts to environmental conditions or irritants. Examples include smoke, strong fragrances, air pollution, changes in temperature, and cold or dry air. These symptoms can resemble those of allergic rhinitis even when an allergic reaction is not involved.
According to the Cleveland Clinic, nonallergic rhinitis can cause a runny nose, sneezing, congestion, and mucus dripping down the back of the throat. Some environmental exposures can also trigger asthma symptoms, although the cause of nasal symptoms and the cause of breathing symptoms may not be identical.
What other symptoms may occur with a runny nose and asthma?
The combination of nasal and breathing symptoms can provide useful information about what may be happening. These examples can help describe a symptom pattern, but they cannot establish a diagnosis on their own.
- Runny nose with sneezing or itchy eyes: These symptoms may occur with allergic rhinitis, particularly when they follow exposure to pollen, dust mites, mold, or pet dander.
- Runny nose with a sore throat or feeling unwell: A respiratory infection may be responsible, especially if coughing or other new symptoms develop at the same time.
- Runny nose after exposure to smoke or strong smells: Nasal irritation or nonallergic rhinitis may be involved.
- Runny nose with wheezing, coughing, or chest tightness: Nasal symptoms and asthma symptoms may be occurring together. New or worsening breathing symptoms deserve particular attention.
- Nasal congestion with mucus dripping into the throat: Postnasal drip can irritate the throat and contribute to coughing, which may overlap with cough associated with asthma.
These symptoms can have more than one explanation. A healthcare professional may consider when they started, what seems to trigger them, how long they last, and whether breathing symptoms change with them.
What can you do if you have asthma and a runny nose?
The most useful next step depends on the likely cause of the nasal symptoms and whether asthma is also becoming harder to control.
- Notice recurring patterns. Record whether symptoms occur during particular seasons, after contact with pets, or around smoke, fragrances, or other irritants. This information may help a healthcare professional identify relevant triggers.
- Reduce exposure to known triggers. If a particular allergen or irritant is known to cause problems, reducing contact with it may help limit symptoms.
- Continue prescribed asthma treatment. Follow your asthma treatment plan. Do not stop or change prescribed asthma medicines because of a runny nose without discussing the change with your healthcare professional.
- Discuss persistent nasal symptoms. If a runny nose keeps returning, interferes with sleep, or affects daily activities, ask about possible allergic rhinitis, nonallergic rhinitis, or other nasal conditions. Treatment depends on the cause and your overall health.
Some medicines used for nasal symptoms may not be suitable for everyone. A healthcare professional or pharmacist can help you choose an appropriate option, especially if you take other medicines or have difficulty controlling your asthma.
When should you seek medical care?
Arrange a medical assessment if your runny nose persists, keeps returning, becomes troublesome, or occurs with worsening asthma symptoms. An assessment may include a review of your medical history, symptom patterns, possible triggers, and examination. Depending on the findings, a clinician may consider allergy testing or tests to assess lung function.
Seek urgent medical help if you develop significant or worsening difficulty breathing, or if your prescribed quick-relief asthma medicine is not helping as expected. Severe breathing difficulty is an emergency. A runny nose alone is not usually an indication of an asthma attack, but it should not distract from concerning changes in breathing.
In summary, asthma does not usually cause a runny nose directly. Allergies, respiratory infections, and nasal irritation are common explanations for why both nasal and asthma symptoms may occur together. Identifying the pattern can help guide appropriate care.