We'll detail eight possible sources of pain under the left armpit as well Breast cancer may be another cause of underarm swelling and pain.
Learn more about the causes of armpit pain and when you should There's a concentration of lymph nodes near the armpit on both sides of the body. but if you notice pain or feel a lump under your arm or in your breast.
A common symptom of breast cancer is pain and swelling around your armpit. It may come from: The spread of breast cancer to.
Armpit pain may also indicate breast cancer. Some people may also experience painful lymph nodes as a side effect of cancer treatments.