The first symptom is often a circular, red, painless sore on your penis and genital area. If left untreated, it can spread and advance to other parts.
It's not uncommon to have small bumps or spots on your penis. But a painful or uncomfortable sore is usually a sign of some kind of underlying.
Worried about a spot, lump or growth on your penis? Here are some possible A painless sore or ulcer on your penis could be caused by syphilis (another STI).