Hard lumps in the armpits without pain may generally be caused by folliculitis, enlarged lymph nodes, subcutaneous lipoma and other reasons. 1. Folliculitis: Folliculitis generally refers to the inflammation of the entire hair follicle triggered by bacterial infection, usually caused by bacterial infection, bad habits and other reasons, there may be fever, headache and other symptoms. 2. Enlarged lymph nodes: Enlarged lymph nodes are generally acute and chronic inflammation caused by pathogenic microorganisms, usually caused by external factors, infectious diseases, etc. There may be symptoms such as abnormal sweating after going to sleep, stopping sweating after waking up and low-grade fever. 3. Subcutaneous lipoma: Subcutaneous lipoma generally refers to benign soft tissue tumors occurring in the superficial, usually caused by external factors, dietary habits, etc. It may have symptoms such as elastic swelling and no tenderness. Patients should identify the cause of the disease and treat it under the guidance of the doctor.