Nasal congestion occurs when the tissues lining the nasal passages become swollen or inflamed, often due to infections, allergies, or irritants. This swelling can block airflow, making it difficult to breathe through the nose. Common causes include the common cold, sinusitis, and allergic rhinitis. Symptoms of nasal congestion may include a stuffy or runny nose, sneezing, and pressure in the sinuses. Treatment options often involve decongestants, saline nasal sprays, or antihistamines, depending on the underlying cause. Staying hydrated and using a humidifier can also help relieve discomfort.