Left arm pain is a common symptom of tendon inflammation, nerve compression or bursitis, which are conditions that can affect any of the joints along the left arm, like the shoulder, elbow or wrist.
Pain in the left arm can also be a sign of a more serious condition, however, like a heart attack, angina or an arm fracture. These conditions will often present with other major symptoms. Left arm pain from a cardiac emergency, for example, may be accompanied by symptoms like chest pain, shortness of breath, sudden cold sweats and dizziness.
If your left arm pain is very intense, sudden, gradually worsening or presents with other serious symptoms, you are advised to seek medical attention for further assessment and treatment as necessary. Mild left arm pain from a sports injury or repetitive use may be managed at home with rest, ice and over-the-counter medications.

Why does my left arm hurt?
Pain in the left arm can be caused by:
1. Heart attack
A heart attack occurs when there is decreased blood flow to the heart, resulting in cellular death. It can cause chest pain that radiates to the left arm, which is very characteristic of a heart attack.
This chest and arm pain can be accompanied by other symptoms, like dizziness, general malaise, nausea, cold sweats or pallor. Read more about the symptoms of a heart attack that you shouldn’t ignore.
How to treat: If you notice any of these symptoms, you should go to the hospital or call 911, especially if you have a history of diabetes, high blood pressure, obesity or high cholesterol.
2. Angina
Angina is characterized by the feeling of chest heaviness, tightness or pain that can radiate to the arm, shoulder or neck. It is also caused by decreased blood flow in the arteries that provide oxygen to the heart. Angina is generally triggered by strenuous activity or intense emotions.
How to treat: Treatment depends on the type of angina the patient is presenting with. The doctor will often prescribe anticoagulants, vasodilators and/or beta-blockers.
3. Bursitis
Bursitis is the inflammation of a bursa, which is a small sac of fluid found within joints. These sacs reduce friction between tendons and bones, but can become inflamed with injury or overuse. Inflammation of the bursa can prompt symptoms like shoulder or arm pain, difficulty lifting the arm above the head, muscular weakness and tingling that radiates down the arm.
How to treat: Bursitis can be treated with anti-inflammatories, muscle relaxants, rest and physiotherapy. Read more about bursitis treatment and then home remedies you can prepare to speed up recovery.
4. Fracture
An arm, elbow or clavicle fracture can cause pain anywhere along the arm. Most people will also experience swelling, visible deformity, inability to move the arm, bruising, numbness and tingling in the arm.
Arm injuries or direct trauma without fractures can also cause pain that lasts for days.
How to treat: If you suspect your arm is fractured, you should seek medical attention immediately. The doctor will likely assess the area and order an x-ray. Treatment involves immobilization of the arm, analgesic and anti-inflammatory medication, and physiotherapy.
5. Cervical disc hernia
A herniated disc is an intervertebral disc in the spine that has bulged out of its spot. Depending on the area of the spine, it can cause symptoms like back pain that radiates to the arms and neck, weakness, tingling and difficulty moving the neck or lifting your arms. Learn more about the different types of hernias and what can cause them.
How to treat: Generally, herniated discs are treated conservatively with analgesics, anti-inflammatories, physiotherapy, osteopathy and exercises like water aerobics or Pilates.
6. Tendinitis
Tendinitis is the inflammation of the tendons caused by repetitive movements. Shoulder, elbow or arm tendinitis can cause symptoms like pain that can radiate to the arm, difficulty moving the arm, arm weakness, or stabbing, cramping shoulder pain.
How to treat: Tendinitis can be treated with analgesics and anti-inflammatories. Cold compresses on the affected area can also help, however it is important to discontinue the activity that triggered inflammation.
In addition to all the above-mentioned causes, left arm pain can also be related to rheumatoid arthritis, lupus or Sjögren syndrome. Check-out the different approaches to tendonitis treatment and how to prevent this condition.
6. Poor circulation
Poor circulation in the left arm from a blood clot or thrombosis can leave the arm feeling heavy and cause tingling or swelling. It may also alter hand color, and leave the hands with a pale or purple appearance.
How to treat: You should consult a doctor if you suspect poor circulation. The doctor will evaluate the arm with a thorough assessment and further testing, like ultrasounds or dopplers. Treatment depends on the underlying cause, and may involve increasing fluid intake, exercises, or medications for more severe cases.
8. Diabetic neuropathy
Diabetic neuropathy occurs due to persistently high blood sugar levels, which can cause damage to the nerves in the body. It can affect the arms, hands or feet and lead to symptoms like sharp pain, burning, tingling and numbness.
Diabetic neuropathy generally affects people with unmanaged diabetes who do not adhere to prescribed treatment.
How to treat: Blood sugar levels should be controlled as directed by an endocrinologist. The doctor may prescribe diabetes medications, like insulin, to normalize blood sugar levels. Symptoms of diabetic neuropathy can be managed with anticonvulsant, antidepressants or opioids, like pregabalin, amitriptyline or tramadol.
Check out teas for blood sugar that you can prepare at home to keep your blood sugars within normal ranges. These should be used as a complement to your prescribed treatment and should not replace your doctor's treatment plan.
9. Rheumatoid arthritis
Left arm pain can occur due to rheumatoid arthritis, which is a chronic inflammatory autoimmune disease. It occurs when the immune system produces antibodies that attack other healthy cells in the body, causing inflammation in the joints.
When rheumatoid arthritis affects the shoulder, elbow or wrist, it can cause persistent pain in the left and/or right arm, swelling, difficulty holding objects and even joint deformity.
How to treat: Treatment for rheumatoid arthritis should be guided by a rheumatologist and includes the use of medications, an anti-inflammatory diet and physiotherapy. Treatment is aimed at relieving pain and swelling to improve quality of life.
10. Thoracic outlet syndrome
Thoracic outlet syndrome, which occurs due to compression of nerves and/or blood vessels in between the clavicle and first rib, may also cause left arm pain.
Generally, thoracic outlet syndrome emerges due to injuries in the area from direct trauma, accidents or repetitive movements. It also commonly affects athletes. Symptoms that can occur with this condition can include arm pain, shoulder pain, neck pain, tingling and difficulty moving the arms.
How to treat: Treatment for thoracic outlet syndrome should be guided by an orthopedic surgeon, who may prescribe analgesics, anti-inflammatories, anticoagulants, physiotherapy or even surgery.
11. Rotator cuff injury
Left arm pain can occur due to an injury in the rotator cuff, which is made up of 4 muscles and 4 tendons that help to move the shoulders.
Injuries in this area can occur due to inflammation from overuse, irritation or repetitive movements. It is most common in athletes and people who work with heavy loads. Symptoms of this condition include pain that worsens with movements, arm weakness and difficulty completing activities of daily living.
How to treat: Treatment for rotator cuff injuries should be directed by a orthopedic surgeon. Treatment is aimed at reducing swelling within the shoulder joint and promoting healing, and may involve cold compresses, physiotherapy, anti-inflammatory medications and corticosteroid injections to the shoulder.