context: If your arm hurts, there could be a number of reasons why. Arm pain is usually described as pain, discomfort, or stiffness that occurs anywhere from your shoulders down to your fingers in one or both arms. Most often, it's caused by an injury or overuse. But there are many other health conditions that can cause your arm to hurt. Pain in your left arm could be related to a heart condition. Angina, which is caused by decreased blood flow to the heart, can cause pain in the arm shoulder. A heart attack can cause pain in one or both arms. A heart attack happens when the oxygen supply to your heart is completely cut off due to a blockage that prevents blood from flowing into the muscle. If you're having a heart attack, your arm pain will probably come on suddenly. You also may experience: Chest pain or pressure Shortness of breath Dizziness Nausea If you're having these symptoms, call 911. Sometimes, you can trace arm pain to a sports injury or simply using it too much. Other times, another condition could be to blame. Here are some other possible causes: Broken bones: If your arm starts to hurt right after a physical injury, you may have fractured it. You might also have swelling, bruising, numbness, or weakness. See your doctor right away so your arm will heal properly. Strain or sprain: An injury can cause damage to your muscles (a strain) or your ligaments (a sprain). Symptoms include pain, swelling, bruising, weakness, and muscle spasms. Both conditions will usually heal on their own, but if your symptoms are severe, you should see your doctor as soon as possible. Tendinitis: This happens when the tendons in your shoulder or arm become inflamed. Those are bands of tissue that connect muscles to bones. One example of tendinitis is âtennis elbow.â You could feel the pain in your shoulder, elbow, or wrist. It could be a result of an injury or â more often â overuse. Rotator cuff injury: This part of your shoulder is made up of muscles and tendons. It allows your shoulder to move or stay in place. As we age, tendons in the rotator cuff begin to wear down or tear. If you have a job where you make overhead motions over and over, you can damage it, too. Symptoms range from a dull ache and weakness in your arm to severe, constant pain. If you suspect a rotator cuff injury, see your doctor. You may need physical therapy. Carpal tunnel syndrome: Doing the same movements over and over with your wrist can cause damage to the main nerve in your hand. It can lead to numbness, tingling, weakness, and pain. In some cases, you can't trace your arm pain to physical injury or overuse. It could be caused by diseased arteries in the upper part of your body. It might also be the result of stress, a new medication, or another medical condition, including: Pinched nerve: This happens when bones or tissues in your shoulder, neck, or elbow press against and compress a nerve. It causes pain, numbness, weakness, and tingling. Herniated disk: These are little cushions between the hard bones (vertebrae) that make up your spine. They allow your back to flex or bend. If one of the disks in your neck ruptures, it could cause a burning pain, numbness, weakness, and tingling or burning in your arms. Autoimmune diseases: If you have one of these conditions, your body's natural defense system (immune system) attacks itself. Some of these -- like rheumatoid arthritis, lupus, and Jorgen's syndrome -- can cause pain in the neck, arms, elbows, wrists, and hands.