Armpit pain can also be caused by acute injuries to muscles or ligaments during ... you can feel more pain in the chest area or under the arm," says O'Hare. Pain often occurs in both armpits ...

Often, armpit pain is a simple case of a strained muscle. "The most common causes ... you can feel more pain in the chest area or under the arm," says O'Hare. Pain often occurs in both armpits ...