Nasal dyspnea is also known as nasal congestion, usually due to two reasons: 1, the most common reason is the common cold, due to viral invasion to the nasal mucosa, caused by the expansion of the blood vessels of the nasal mucosa, and produce a large amount of secretion, that is, snot, at the same time, make the nasal mucosa and the turbinate of the nose edema, caused by the nasal dyspnea. 2, due to allergies, allergic rhinitis is actually due to contact with allergic substances, making the nasal mucosa after swelling. Swelling, the patient may have an itchy nose, sneezing, is one of the common causes of the nose. Specifically what is the cause, must go to the hospital to do the examination, allergen testing or nasal mucoscopy or, look at the condition of the nasal turbinates, to be able to determine the cause of the nose not ventilated.