What causes redness and swelling of the glans penis in men?

Redness and swelling of the male glans penis may be caused by various factors. Common causes include long foreskin, balanoposthitis, allergic reactions, and genital herpes. A long foreskin can easily accumulate smegma, leading to infection and subsequent redness and swelling. Balanoposthitis is an inflammation caused by bacterial or fungal infections, characterized by symptoms such as redness, swelling, and itching. Allergic reactions—for instance, those triggered by contact with allergens—can also cause redness and swelling of the glans. Genital herpes, a viral infection, is another condition affecting the genital area that can lead to discomfort including redness, swelling, and pain in the glans penis.