Sore and swollen glands under the armpits are likely swollen lymph nodes, WebMD explains. Swollen lymph nodes under the armpits may be indicative of numerous types of infections, including skin infections.
Though most people associate lymph nodes with being in the neck area, there are several other places in the body they appear, according to WebMD. When the glands become swollen, they may cause pain when pressed upon or touched, and the skin around the affected area may become red and tender. Specific treatments for swollen glands under the armpits are dependent on what is causing them, but typical treatments include over the counter pain medication or anti-inflammatory drugs and warm presses.