The most likely cause of a sharp pain in the shoulder and arm is injury to the rotator cuff, as Healthline explains. Osteoarthritis, bursitis, tendinitis and tendon sheath inflammation may also cause sharp pain in the shoulder. Sometimes, people may feel shoulder pain from a problem in their neck, such as arthritis or pinched nerves, according to Mayo Clinic. Occasionally, pain in the shoulder and arm results from a heart attack, as WebMD reports.
The rotator cuff is a group of four muscles that aid shoulder movement and can tear easily, as described by Healthline. Tendinitis refers to inflammation of the tendons connecting these muscles, while arthritis affects the joint. Bursitis occurs when the fluid-filled sacs, or bursa, that cushion the joint become inflamed. A person may have more than one of these conditions, and each person may experience the pain differently. Some patients may experience acute pain or a dull or aching pain, but some may not develop symptoms for years.
Pain in the shoulder from a problem in the neck or chest is known as referred pain, reports Mayo Clinic, and it occurs because the brain does not always distinguish which nerves are sending the signal. If a heart attack is causing the shoulder and arm pain, it may cause other symptoms, such as nausea, dizziness, and throat or jaw pain, as WebMD indicates.