Penile foreskin inside redness may be due to the foreskin scale and other foreign body stimulation, foreskin glans as well as acute urethritis, allergies and other conditions, it is recommended that further examination to clarify the cause. 1. Foreign body stimulation, overstimulation: if you do not pay attention to personal hygiene, do not do a good job of timely cleaning, may lead to the accumulation of foreskin scale, or underwear replacement is not timely, etc. may lead to the glans by the chronic stimulation of foreign bodies and present a red and swollen state; in addition, if there is excessive masturbation, violent sex life, etc. will also lead to the glans is overstimulated and present a red and swollen state. 2. Circumcision and glansitis: for those who are circumcised or circumcised, the long-term chronic stimulation of the foreskin scale can easily induce fungal or bacterial circumcision and glansitis, which can also cause redness inside the foreskin of the penis. 3. Acute urethritis: If there is urethral obstruction, unclean sex, etc. may induce bacterial urethritis, gonorrhea urethritis and other acute urethritis, which will also lead to the emergence of the urethral opening of the redness, swelling, and even pain and other manifestations. The above symptoms may also be caused by other factors, therefore, it is recommended that patients seek further examination in a timely manner in regular hospitals to clarify the cause of the disease and deal with it in a timely manner, so as to strive for early recovery.