Armpit masses are most commonly found in women and also in men, mainly due to several factors: 1. Underarm masses with pain can be found in both men and women called sebaceous cysts. There are hairs in the armpit, and after the sebaceous glands under the hairs are blocked from secreting, it leads to poor drainage of the sebaceous cysts leading to infection. If the cyst is a sebaceous gland, local anti-inflammatory treatment and surgical excision can be performed if necessary. The diagnosis is generally not difficult through the doctor’s judgment. 2. For the common axillary masses in women, special attention should be paid to the fact that, first of all, mammary gland hyperplasia, with the change of menstrual cycle in women, the glands of the mammary glands will also produce cyclical changes, especially in the 4-5 days before the menstrual cycle, there may be pain, and the axilla will sometimes be enlarged accordingly. It will be relieved naturally after the menstrual cycle. If necessary, ultrasound will be done to clearly determine; 3. Parammary gland, normal breast for the front chest, in the armpit there is a parammary, the so-called parammary is also the tissue of the breast, the formation of the mass will also produce the same as the breast, with the cycle of change will produce pain. In the case of parametrial breast, the diagnosis is usually made by ultrasound. If the parametrium affects the beauty or pain, it can be removed surgically, usually under local anesthesia or general anesthesia; 4. The most common type of parametrium, especially for middle-aged women and above, if a lump is found under the armpit, special attention should be paid because the most common tumor in women is still breast cancer. After breast cancer, the main lymphatic transfer pathway will be transferred to the armpit and the corresponding axillary lymph enlargement. So touch the lymph in the armpit and touch the lump in the armpit. First of all, we should feel whether there is a lump in the breast through self-examination, and then conduct ultrasound examination in time, and if breast cancer is found to cause enlarged lymph nodes in the armpit, we should treat it accordingly.