Rhinitis medicamentosa (RM) refers to nonallergic inflammation in the nasal mucosa which is caused by the abuse of nasal decongestant and it often occurs in patients with allergic/nonallergic rhinitis along with nasal congestion. RM is characterized by nasal congestion based on long-term use of nasal decongestant, without rhinorrhoea or sneezing. The signs of RM include nasal swelling, thickening, loss of elasticity, and loss of sensitivity to the decongestant. The histological changes of RM are loss of nasal mucosa cilia, squamous epithelium metaplasia, edema of epithelium cell, hyperplasia of goblet cell, increased expression of epidermal growth factor receptor and infiltration of inflammatory cells, etc. There is no precise diagnosis standard for RM, making it even harder for its objective diagnosis. Patients with RM should immediately stop using nasal decongestant, in stead of using nasal glucocorticoid spray for the recovery of the nasal mucosa's function.