Armpit pain is not necessarily a sign of cancer, but needs to be clarified after systematic examination in a regular hospital. There are many causes of armpit pain, including overexertion, inflammation, muscle strain and other factors. These factors generally belong to benign factors, and the symptoms can be improved after patients improve in daily life, such as taking more rest, avoiding overexertion, developing good living habits and keeping a happy mood. Another condition is armpit pain caused by tumor factors, such as breast cancer and lymphoma. If breast cancer causes armpit pain, the patient will also suffer from skin deterioration, hard lumps in the breast area and chest tightness. If the pain is caused by lymphoma in the armpit, the patient will have hard lumps and enlargement in the armpit. Therefore, if armpit pain occurs, it is recommended that patients should go to a regular hospital for detailed examination in a timely manner to clarify the diagnosis and cause of the disease and then give appropriate treatment.