What are the possible causes of sharp pain under my right armpit?

There are a few things that might make you feel a sharp pain under your right armpit. One cause is swollen lymph nodes—a condition called adenopathy. Lymph nodes can become painful when they swell because your body is fighting an infection or dealing with an autoimmune condition like mixed connective tissue disease or psoriatic arthropathy. When the lymph nodes are enlarged and tender, you might feel a quick, sharp pain in your armpit. Another possible reason is a skin issue affecting the sweat glands, such as axillary osmidrosis. Although this condition usually changes how your skin smells, if the bacteria balance on your skin is disturbed, it can sometimes lead to irritation or even infection, causing pain. Also, besides these, injuries or strain in the muscles or tissues around your armpit may cause similar sharp pain. If the pain continues, gets worse, or comes with other symptoms like fever or swelling, you can use a free symptom checker to help identify potential causes before speaking with your doctor, who can provide a proper diagnosis and recommend the best treatment to help you feel better.