(BPT) - If you live with asthma and struggle with chronic sinus problems, the two conditions may be more connected than you think.

Chronic rhinosinusitis is long-term swelling of the nose and sinus passages that lasts for 12 weeks or more. It causes ongoing congestion, facial pain or pressure, postnasal drip and difficulty with sense of smell.

Sometimes chronic rhinosinusitis can cause small growths in the nose called nasal polyps. These are soft, painless, noncancerous lumps. Globally, about 5-12% of people live with chronic rhinosinusitis, and up to 30% of them also develop nasal polyps. When both conditions are present, it's called chronic rhinosinusitis with nasal polyps (CRSwNP).

How does CRSwNP affect asthma?

Chronic rhinosinusitis with nasal polyps can worsen asthma. The nose, sinuses and lungs are part of a "united airway." Any inflammation in the upper airways can trigger asthma symptoms and flare-ups in the lower airways. Polyps can also disrupt airflow.

Due to the chronic nature of the conditions, people with CRSwNP and asthma tend to struggle with worse quality of life.

What causes CRSwNP?

The exact cause of CRSwNP is not fully understood, but several factors contribute to its development.

Sinuses and nasal passages are lined with a protective mucosal barrier that blocks germs and irritants. In people with CRSwNP, this barrier is weakened. When microbes and irritants get through, they can trigger long-lasting inflammation in the sinuses. Over time, this constant inflammation can change the structure of sinus tissue, leading to the growth of nasal polyps.

People with both CRSwNP and asthma may also have high levels of immunoglobulin E (IgE) antibodies and/or eosinophils in their body.

• IgE is a protein in your blood that helps fight germs. In some patients, it can cause allergic reactions.
• Eosinophils are white blood cells that fight infections. Too many can increase inflammation.

It's important to get an accurate diagnosis. Your healthcare provider will take a detailed history of your symptoms and perform a physical exam. Additional tests may include:

• Lung function tests. These can help diagnose or reveal the severity of asthma.
• Blood tests. These can help determine levels of IgE and eosinophils for both asthma and CRSwNP.
• Sinus CT scan. Images of your sinuses and nasal cavity can reveal the severity of CRSwNP.
• Nasal endoscopy. This involves a tiny camera inserted into your nasal passages to search for polyps.
• Allergy tests. These help identify allergies that could be triggering symptoms. (They are also used to diagnose allergic asthma.)

CRSwNP triggers often overlap with asthma triggers. They include allergens such as pollen, mold or pets. Nonallergic triggers include respiratory viruses, tobacco smoke, air pollution and cold, dry air.

How to treat asthma and CRSwNP together

Asthma and CRSwNP require different treatments. Medications are available. Working together with your doctor to manage both conditions gives you the best chance for relief and better breathing.

For asthma, it's essential to keep symptoms under control. Most people use a daily controller inhaler with an inhaled corticosteroid. These medications can help reduce inflammation and keep the airways open. Quick-relief inhalers are also available for sudden asthma symptoms or attacks.

For CRSwNP, corticosteroid nasal sprays are the first-line treatment. They can help reduce swelling and inflammation in the nose. A short course of oral corticosteroids can shrink polyps and improve a stuffy nose, but long-term use can cause serious side effects. If medications aren't working, surgery to remove the polyps may be an option.

Biologic medications can treat asthma and CRSwNP together. Given as injections every 2-4 weeks, they are often a good choice for people with moderate to severe symptoms who haven't found relief with other treatments.

Biologics target the underlying inflammation, not just the symptoms. They help reduce airway swelling, improve breathing and can even shrink nasal polyps. Some biologics are specifically approved for people with high IgE or eosinophil levels. This can help patients maintain control of both asthma and CRSwNP.

Healthcare providers may also recommend lifestyle changes, such as avoiding triggers. This can also help reduce asthma and CRSwNP symptoms and help you feel better.

How to start taking control

If you have asthma with chronic sinus symptoms, it's time to meet with your healthcare provider. Consider seeing a specialist such as a board-certified allergist. Ask about testing for CRSwNP, since sinus problems and nasal polyps may be making your asthma symptoms worse.

Visit AllergyAsthmaNetwork.org to learn more about asthma and CRSwNP.