Armpit is the armpit, axillary cyst pain when pressed may be related to the cyst infection and related. Axillary cysts are cystic masses growing in the armpit area, the contents of the cysts are usually liquid of different nature, most of the cysts are benign lesions, usually no clinical symptoms, and slow growth, they can disappear on their own. Most cysts are benign lesions with no clinical symptoms and slow growth, which may disappear on their own. A small number of cysts may be caused by malignant tumors of the breast or lungs that have metastasized to the axilla. Because of the rich sweat glands in the armpit, sweating is more, when the activity of the cysts can cause friction on the armpit tissue, which can easily lead to infection of the cysts, and redness, swelling, heat, pain and other inflammatory reactions can occur. When cysts are found in the armpit, you should actively go to the hospital for timely treatment to avoid further deterioration of the condition.