The hard bumps in the two armpits are commonly caused by the following reasons: first, enlarged lymph nodes, lymph nodes are part of the body’s immune organs, which have many lymphocytes and immune cells, when the body suffers from heterogenous invasion, such as bacterial infection or viral infection, it can lead to an increase in lymphocytes, it will cause the enlargement of lymph nodes. This can generally be treated by drinking warm water and taking oral medications to clear heat and lower fire, such as Jin Yin Hua Oral Liquid and Shuang Huang Lian Oral Liquid, etc. If necessary, oral antiviral medications or antibacterial medications can also be used to treat the lymph nodes. However, some other diseases can also lead to swollen axillary lymph nodes, such as autoimmune system diseases, hematological system diseases, lymphoma, etc. These need further investigation of blood routine, tumor markers, including lymph node biopsy to clarify the nature. Second, skin allergy, when contact with some inappropriate substances will lead to swelling and enlargement of the axillary skin, which needs to avoid allergens. Thirdly, hair follicle infection can also lead to swelling in the armpit. In short, if the swelling continues to appear, it is necessary to go to the hospital in time to clarify the cause.