It is recommended to go to the hospital for a relevant physical examination to clarify the specific causes. 1. Below the glans belongs to the most elevated part of the coronal sulcus, which can be seen similar to edema-like changes, but belongs to the normal structure. It is not accompanied by local redness, pain, or any discomfort, and is mostly a normal physiological bulge. It is recommended to be informed by a doctor after specialist examination whether it is abnormal or not. 2. Glansitis, which can appear as local redness and swelling of the glans, mostly accompanied by abnormal discharge, accompanied by redness of the glans surface, or accompanied by local exudation, pain and other changes. If you have a tumor of the penis, you can see that the surface of the glans is not smooth, with cauliflower-like or nipple-like protrusions, with ulceration and bleeding, with pain, and so on. Local biopsy is needed to determine whether there is penile cancer.