Swollen penis head may be caused by infectious factors, allergy, trauma, local irritation, bad sexual habits and so on. 1. Infectious factors: If men have prepuce glans inflammation, such as fungal, bacterial, trichomonas and other infections, it will lead to redness, swelling, pain and other symptoms of the penis head. 2. Allergy: when using sanitary products or washing products, it may cause irritation to the penis head area, and then allergic reaction will occur, which will also lead to swelling and itching. 3. Trauma: If the head of the penis is excessively squeezed, or if too much force is exerted during sex, it may lead to localized injury, causing redness, swelling and pain in the head of the penis. 4,Local stimulation: Men may have swollen penis head if they have excessive masturbation or local stimulation for a long time, such as using alcohol to sterilize the penis, repeatedly touching the genitals with their hands or rubbing with underwear repeatedly. It is necessary to stop the related stimulation and then observe the improvement of the enlargement. Poor sexual habits: If there is unclean sexual contact, infected with gonococcus, mycoplasma, chlamydia, etc., the penis head may be enlarged, and at the same time there will be urethral urethral urethra redness, swelling, increased secretions. The swelling of the glans may also be caused by other factors, it is recommended that patients go to the regular hospital for relevant examinations to clarify the cause of swelling and treatment, and strive for early recovery.