The common causes of pain in the lateral axilla of patients are the following: First, acute infection of the local skin soft tissue, such as folliculitis, or sebaceous cyst with purulent inflammation, the pain symptoms in this case need to actively control the infection, and the pain symptoms will gradually improve after the inflammation is controlled. Second, some patients with intercostal nerve pain will also show pain in the outer part of the axilla, which can be alleviated by local topical rubbing of Furtalin ointment. Female patients with mammary gland hyperplasia or breast nodules will also experience radiating pain in the lateral axilla. Patients can check the severity of the condition through breast ultrasound, and if necessary, they can take oral drugs such as prolotherapy pills, flat elimination tablets and breast nucleus dispersion tablets to improve the axillary pain symptoms caused by mammary gland hyperplasia. For patients with pain symptoms, it is important to identify the cause and take symptomatic treatment in order to achieve better results.