Boys sex organs suddenly become very smelly may be poor hygiene habits, or consider the glans, urethritis and other diseases. 1. poor hygiene habits: if the boys have not bathed for a long time, sweaty, strenuous exercise, may lead to local bacterial growth, the emergence of intolerable odor. 2. glansitis: boys sexual organs suddenly become very smelly is also considered to be due to glansitis, glansitis may be caused by infection, excessive friction, allergies, excessive sweating, circumcision and other factors. Patients may appear local erythema, edema, erosion and other symptoms, some patients may appear local odor abnormalities. 3. Urethritis: Urethritis may be caused by gonococcal, non-gonococcal pathogen infection, patients may appear urinary frequency, urinary urgency, abnormal secretion and other symptoms, which may be manifested as the boy’s sexual organs suddenly become smelly. In addition, other reasons such as tumor necrosis foci may also lead to boys’ sexual organs suddenly become very smelly, and patients are advised to go to regular hospitals for diagnosis and treatment.