There are two general causes of smelly boogers: 1. Atrophic rhinitis. 2. Chronic maxillary sinusitis leading to purulent secretions, resulting in smelly boogers. Atrophic rhinitis is generally an autoimmune disease, due to endocrine disorders, vitamin A, B, D deficiency, or low blood cholesterol levels, as well as damage to the nasal mucosa caused by chronic rhinitis, chronic sinusitis, or nasal surgery. Clinical symptoms include nasal congestion, rhinorrhea, impaired sense of smell, and nasal malodor, the source of which is due to infection by the bacterium Rhinobacter oxytoca. In terms of treatment, there is no specific treatment for atrophic rhinitis. Patients can take multivitamin supplements, as well as use nasal rinses and also use glucose glycerin nasal drops to prevent nasal discharge. In the case of an acute attack of chronic maxillary sinusitis, the patient will experience fever, headache, yellow nasal discharge, facial swelling and other related symptoms, and a clear diagnosis can be made by examining sinus CT. In case of acute maxillary sinusitis, symptomatic anti-inflammatory treatment with oral anti-inflammatory drugs, such as cefixime, roxithromycin or azithromycin, is required. In case of recurrent maxillary sinusitis, surgical treatment is required, and endoscopic sinus opening can be performed. Post-operative exercise and avoiding colds can slowly cure the condition.