The first reason is congenital. Some patients may have a family history of genetic predisposition, or the pregnant woman may have been exposed to some viral invasion, radiation exposure, drug application and other related factors during pregnancy, or genetic mutations may lead to abnormal embryonic development, causing the patient’s nostrils to become enlarged. The second reason is that some patients repeatedly pick their noses for a long time, resulting in enlarged nostrils, which is caused by bad habits, especially in patients with allergic rhinitis and chronic hypertrophic rhinitis. The third reason, some patients may have nasal cavity long things, such as bilateral nasal cavity diffuse polyps, nasal cavity NKT lymph or nasal tumors and so on, tumors in the nasal cavity extensive growth can squeeze the nostrils, resulting in nostril hypertrophy, nostril enlargement may. The fourth reason is that some patients have endocrine system diseases, such as those with acromegaly, can also show enlarged and enlarged nostrils. All in all, patients who have enlarged and enlarged nostrils need to be clinically analyzed according to the patient’s condition to see what exactly causes the patient.