The armpit refers to the armpit of the human body, if this place grows fleshy, the most common is localized lipoma or sebaceous cyst, if it is a lipoma, the fleshy drop is usually irregular when touched, and the texture is relatively soft, there is no pain when pressed, the boundary is relatively clear, and the activity is relatively high. If it is a sebaceous cyst, the shape is mainly round or oval, and local inflammation will be painful when pressed, or there will be local redness, swelling, heat and pain. If the inflammation is very serious and leads to pus, there may be skin breakdown and pus flow. In addition, there may be obese people, the fat pad under the skin of the armpit is thicker, will also feel like a meat flab, the above cases can be identified through local ultrasound.