A long flat lump in the groin without pain is mainly considered to be related to small localized hernia, spermatic sheath effusion, inguinal lymphoma, etc. Generally, it is necessary to choose a treatment plan such as surgery or medication according to the specific cause of the disease. 1. Small localized hernia: If there is a small hernia in the inguinal area, such as a hiatal hernia, it usually does not produce obvious pain symptoms, but it is easy to form a localized long flat lump phenomenon. 2. spermatic cord syringomyelia: if there is a spermatic cord syringomyelia problem, the local increase in fluid is easy to trigger the phenomenon of swelling, so there will be a long flat lump in the groin of the symptom, but the early stage will not cause obvious pain. 3. Inguinal lymphoma: if there is lymphoma in the groin, usually the growth of local tumor is easy to produce the phenomenon of a long flat lump in the groin, but it will not cause obvious pain in the early stage. If there are obvious structural changes, affecting local function, usually need to be treated by surgery. In the process of recovery, pay attention to dietary regulation, eat less spicy and stimulating food, and do not smoke and drink alcohol, so as not to affect the recovery. Special reminder, the groin appeared long flat lumps do not hurt the situation, we should promptly consult a doctor to determine the cause of the disease, and give symptomatic treatment, so as not to delay the condition.