A painful lump in the groin in females and males, specifically located on one side, is most likely caused by an enlarged lymph node, a skin infection like an skin abscess or cyst, an infected ingrown hair on the groin, or a symptom of a sexually transmitted infection.

If the cyst ruptures beneath the skin, its contents can infect surrounding healthy tissue. An infected cyst may appear flushed and swollen and may be tender or warm to the touch. There are two types of cyst that can develop in or near the groin: epidermoid cysts and sebaceous cysts.

A lump in the groin or inner thigh on males and females can be caused by a variety of conditions that range in severity, from common conditions such as groin abscesses and skin cysts, to rarer conditions like lipoma or a groin hernia. Read more below about what may be causing the lump in your groin and how your doctor may treat it.