Hard lumps on the inner thigh without pain may be caused by lymph node enlargement, lipoma, sebaceous cysts and other diseases. 1. Enlarged lymph nodes: If the organs near the groin are infected or malignant tumors and other reasons, it can cause the lymph nodes to increase in size, which is manifested as hard lumps on the inner thigh without pain. Usually, those who are accompanied by pain often suggest acute inflammation, and those who are not accompanied by pain often suggest lymph node metastasis of malignant tumor. 2. Lipoma: it is a kind of slow-growing fat mass with soft texture and painless, mostly occurring in the subcutaneous of limbs and trunk, but also in deep tissues, such as occurring in the inner thighs, which can cause hard lumps on the inner thighs without pain. 3. Sebaceous cysts: cysts formed by sebum accumulation in the glands, most common in adolescent people, such as occurring in the inner thighs, can cause hard lumps on the inner thighs without pain. If the pressure on the surrounding tissues, it can be accompanied by pain; if the complication of infection can cause redness, swelling, pus, etc.. There are many other causes of hard lumps on the inner thighs without pain, so it is recommended that patients consult a doctor in a timely manner to identify the cause of the disease and follow the doctor’s instructions for further treatment or therapy.