What Are the Symptoms of Sexually Transmitted Infections (STIs) in Men?
Sexually transmitted infections (STIs), also known as venereal diseases, are infections primarily transmitted through sexual intercourse and predominantly affect the genital area. The five classic STIs include syphilis, gonorrhea, chancroid, lymphogranuloma venereum, and granuloma inguinale. Specific symptoms of STIs in men are as follows:
① Ulcers on the external genitalia
For example, a round, cartilage-hard, painless, solitary ulcer is highly suggestive of a hard chancre (primary syphilis); a soft ulcer with jagged, irregular margins, relatively shallow depth, associated pain, multiple lesions, and purulent exudate strongly suggests chancroid; an ulcer evolving from a cluster of vesicles—soft and painful—is typically indicative of genital herpes.

② Genital or perianal growths (lesions)
Multiple, infiltrative, grayish-white, flat, elevated papules or nodules appearing on the external genitalia or perianal region—moist, prone to erosion, and malodorous—are characteristic of flat condylomata (flat warts). Pinkish or gray-brown, pedunculated, cauliflower- or cockscomb-shaped warty lesions in these areas—easily bleeding—are typical of anogenital warts (condylomata acuminata). Small, millet-sized, dome-shaped papules with central umbilication, a waxy surface sheen, and expressing a cheese-like substance upon puncture suggest molluscum contagiosum.
③ Urethral discharge
Purulent, thick, yellowish discharge from the urethral meatus—particularly prominent upon waking—is highly suggestive of acute gonorrhea; whereas clear, viscous, scanty urethral discharge points toward non-gonococcal urethritis.