Definition: Endangeitis is a condition that refers to inflammation of the lining of the nose and sinuses. It can cause pain, congestion, and difficulty breathing. Symptoms may include nasal congestion, runny nose, sneezing, and a sense of irritation or burning in the eyes. In severe cases, endangeitis can lead to permanent damage to the sinuses and nose. Treatment typically includes over-the-counter medications like ibuprofen and decongestants to reduce symptoms and relieve nasal congestion.