What Causes Sudden Left Arm Pain?

Sudden left arm pain can be unsettling. While many causes are harmless, some require prompt medical attention. Understanding the potential triggers and warning signs can help you decide when to seek care—and when you might simply need rest or gentle stretching.

Cardiac Causes

Heart-related pain often radiates to the left arm. According to the 2013 ACCF/AHA guidelines for ST-elevation myocardial infarction¹, prompt recognition of symptoms saves lives.

• Myocardial infarction (heart attack)
– Often feels like squeezing, pressure, or heaviness in the chest that spreads to the left shoulder, arm, neck or jaw.
– May be accompanied by sweating, nausea, shortness of breath or lightheadedness.
– Can occur at rest or during exertion—people with diabetes or older adults may experience “silent” heart attacks with minimal chest discomfort.
• Angina pectoris (heart “cramp”)
– Transient chest pain or tightness from exertion or stress, often improving with rest or nitroglycerin.
– May radiate to the left arm, shoulder, back or jaw.
• Aortic dissection
– A tear in the inner wall of the aorta can cause sudden, severe chest pain radiating to the back and left arm.
– Often described as “tearing” or “ripping” pain, with possible differences in blood pressure between arms.

When to seek immediate help for cardiac causes:
• Chest discomfort plus any arm, neck or jaw pain
• Shortness of breath, sweating or nausea
• Faintness or sudden fatigue

Musculoskeletal Causes

Strains, sprains and overuse injuries often lead to localized arm pain that worsens with movement.

• Muscle strain or tendonitis
– Resulting from lifting, repetitive activities (e.g., typing, gardening), or a sudden jerk.
– Pain typically worsens when you use the affected muscle and eases with rest.
• Bursitis
– Inflammation of a shoulder or elbow bursa can refer pain down the arm.
– Often tied to overuse or aging.
• Rotator cuff injury
– Tears or inflammation around the shoulder joint can radiate pain into the upper arm.
– Pain may worsen at night or when lifting the arm above shoulder level.
• Costochondritis
– Cartilage inflammation where ribs attach to the breastbone can mimic heart pain and sometimes spreads into the arm.

Key clues for musculoskeletal pain:
• Pain tied to activity or certain movements
• Tenderness when pressing on muscles, joints or tendons
• Improvement with rest, ice, heat or over-the-counter pain relievers

Neuropathic and Spine-Related Causes

Nerve compression or irritation in the neck and shoulder region can produce sharp, shooting arm pain.

• Cervical radiculopathy (“pinched nerve”)
– Herniated disc or bone spur in the neck presses on a nerve root.
– Pain, tingling or numbness may travel from the neck into the shoulder, arm and hand.
• Brachial plexus injury
– Trauma or stretching of the network of nerves supplying the arm can cause burning pain and weakness.
• Thoracic outlet syndrome
– Compression of nerves and blood vessels between the collarbone and first rib causes aching, numbness or tingling down the arm.

Signs pointing to nerve involvement:
• Electrical shock–like or burning sensations
• Numbness, tingling or weakness in the hand or fingers
• Neck pain or stiffness accompanying arm discomfort

Vascular and Pulmonary Causes

Although less common, blood vessel or lung conditions can refer pain to the left arm.

• Pulmonary embolism (PE)
– Blood clot in the lung can cause sudden chest pain that may radiate to the arm, along with shortness of breath, rapid heart rate or cough.
• Pancoast tumor
– Lung cancer at the top of the lung may invade nerves serving the arm, producing persistent shoulder and inner-arm pain.
• Peripheral arterial disease
– Blocked arteries in the arm can cause cramping pain or weakness with activity.

Warning signs for serious vascular or lung issues:
• Sharp chest pain with breathing or coughing
• Sudden breathlessness, rapid pulse or coughing up blood
• Arm pain with coolness, paleness or swelling

Gastrointestinal and Other Causes

Sometimes pain from the gut or other sources can be felt in the left arm.

• Esophageal spasm or reflux
– Intense heartburn or esophageal muscle spasms can feel like chest pressure and spread to the arm.
• Gallbladder pain
– Although usually on the right side, some people feel referred discomfort in the left shoulder or arm.
• Shingles (herpes zoster)
– Early symptoms include burning or tingling pain in a band along the chest or arm, followed by a rash.
• Arthritis and autoimmune conditions
– Inflammatory joint diseases can affect shoulder or elbow joints, sending pain into the arm.

Features suggesting non-cardiac causes:
• Association with meals, reflux or digestive discomfort
• Rash or skin changes before pain onset
• Gradual onset, stiffness or swelling of joints

When to Seek Medical Help

Left arm pain that’s sudden, severe or accompanied by any of the following should prompt an urgent visit to the emergency department:
• Chest pain, pressure or squeezing
• Shortness of breath, sweating, nausea or lightheadedness
• Pain spreading to the jaw, back or other arm
• Fainting, rapid heartbeat or sense of impending doom

For milder or recurring pain, consider a free online symptom check for to help guide your next steps. However, online tools are not a substitute for medical advice.

Preventing and Managing Left Arm Pain

• Maintain good posture when sitting, typing or lifting
• Use ergonomic workstations to reduce strain
• Warm up and stretch before exercise; use proper techniques when lifting
• Take breaks during repetitive activities
• Apply ice or heat packs, and consider over-the-counter anti-inflammatory medications as directed
• Strengthen shoulder and arm muscles with guided exercises or physical therapy

Key Takeaways

• Sudden left arm pain has many potential causes—from heart attacks to muscle strains to nerve issues.
• Recognize emergency signs: chest pain, breathlessness, sweating, fainting or pain spreading to other areas.
• Musculoskeletal and nerve-related causes often improve with rest, ice, heat, gentle stretches and ergonomic changes.
• When in doubt—especially if pain is severe, persistent or accompanied by other symptoms—speak to a doctor.

Nothing in this information replaces professional medical evaluation. If you experience life-threatening or serious symptoms, seek immediate care or call emergency services. Always speak to your doctor about any concerns regarding left arm pain.

References

1. O’Gara PT, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: Executive summary. J Am Coll Cardiol. PMID: 24561304.