Pins and needles pain under the armpit may be due to intercostal neuralgia, axillary lymphadenitis, coronary heart disease and other causes. 1. Intercostal neuralgia: it may be caused by herpes zoster, thoracic spine tuberculosis, thoracic spine fracture and other factors, and it will appear the symptom of nervousness in the chest, and when it involves the upper chest, it may appear the pain like pins and needles in the armpit. 2. Axillary lymphadenitis: it is usually caused by bacterial infection in the soft tissues around the armpit, and the inflammation will spread to the lymph nodes in the armpit, causing axillary lymphadenitis, which can cause pain like pins and needles under the armpit. 3. Coronary heart disease: usually due to coronary artery atherosclerosis, myocardial oxygen consumption increases, resulting in insufficient oxygen supply to the myocardium will appear anterior region of the heart pain, can be radiated to the shoulders, armpits, arms and other parts of the armpit will appear under the armpit pain like pins and needles. Pins and needles pain in the armpits can also be caused by other diseases, patients should go to the hospital for examination, to clarify the cause of the disease, and actively treat it, so as not to delay the condition.