Sharp pain in the left shoulder can be caused by a heart attack, especially if the pain radiates from the chest, down the left arm, and up to the neck and left jaw, explains Medline Plus. An individual experiencing this type of pain needs to call emergency medical services immediately.
Because the shoulder is one of the most-active joints in the human body, left and right shoulder pain can be caused by a range of other conditions from arthritis and bone spurs of the shoulder joint; inflammation of the bursa sac that cushions the bones and tendons; and broken, dislocated or separated bones and tendons, according to Medline Plus.
Treat minor sprains and strains by icing the area for 15 minutes intervals up to four times a day for three days and resting the joint. Over-the-counter acetaminophen can help to reduce any pain and swelling associated with the injury, as noted by Medline Plus.
Consult a doctor if fever and motility problems accompany the pain or if the pain persists for more than a week. In order to prevent shoulder injuries, a person needs to recover fully from previous injuries by consulting a physical therapist, doing regular stretching and strengthening exercises, and icing the shoulder as needed, as stated by Medline Plus.