If you have small lumps with pain in your arm, it may be a sign that there is an infection or inflammation. “Your lymph nodes are located below the arms and neck,” said Jeremy Allen, medical director of American Family Care in the Alabama region. When they become inflamed or infected, they become enlarged and feel pain. They are located in a place where the symptoms are easily caught if there is any problem. Infections caused by fungi or bacteria or viruses in the body can cause the lymph glands to swell and feel pain. It should also be kept in mind that swelling of the lymph nodes can also be a symptom of some cancers. Therefore, if you have such symptoms, the doctor is recommending an assessment.