It is not painful or itchy to feel soybean-sized hard lumps under the armpits, which may be caused by sebaceous cysts, folliculitis, enlarged lymph nodes and other reasons. 1. Sebaceous cysts: sebaceous cysts can exist under the skin, is due to sebaceous gland duct blockage caused when the cysts are small, it is not easy to observe, when touched with the hand, you can feel the soybean-sized hard lumps, painless and itchy. 2. Folliculitis: high levels of androgen hormones in the body, eating greasy and spicy, do not pay attention to skin cleaning and other factors, can promote sebaceous gland secretion increases, the mouth of the hair follicle is blocked, induced folliculitis, manifested as red follicular pimples, painless and itchy. 3. Enlarged lymph nodes: aseptic inflammation and hyperplasia of the lymph nodes in the armpits may lead to the appearance of hard pimples, which are painless and itchy. The armpit touched soybean-sized hard pimples and does not hurt and itch may have other reasons, it is recommended to go to the regular hospital in time, clear cause, under the guidance of the doctor for standardized treatment.