what causes underarm pain
1 Sweating/Irritation Interestingly, another forgotten cause of underarm pain is sweating. 2  Sweating itself doesn't lead to underarm pain, but what it does do is irritate the skin, which in turn can cause itching or burning that may result in pain.
In this way, underarm pain can actually cause anxiety, rather than the other way around. Checking if you lymph nodes are swollen is something you can do yourself: simply feel under your arms and check for any small, hard lumps.