What could be causing my arm weakness and tingling?

Arm Weakness and Tingling: Emergency Evaluation Required

You need immediate emergency evaluation to rule out acute stroke, which is the most critical diagnosis when arm weakness and tingling occur together—this combination represents two of the three cardinal stroke warning signs and requires assessment within minutes to hours to prevent permanent disability or death. 1, 2

Immediate Life-Threatening Causes to Rule Out First

Acute Stroke (Highest Priority)

• The combination of arm weakness with tingling has a 72% probability of stroke if accompanied by facial weakness or speech changes, and even isolated arm symptoms represent high stroke risk. 1, 2
• Middle cerebral artery (MCA) territory stroke is the most likely vascular territory when arm weakness occurs, particularly if bilateral arm involvement is present. 1, 3
• If symptoms started within 48 hours, you are at VERY HIGH risk (up to 10%) for completed stroke within the first week, with highest risk in the first 48 hours. 1, 2
• Call 9-1-1 immediately—do not drive yourself or wait to see if symptoms improve. 1

Acute Arterial Occlusion

• Check if you can feel your radial pulse at the wrist on both arms—absent pulse indicates acute arterial occlusion requiring emergency vascular surgery. 2
• Look for the "6 P's": Pain, Pallor (pale skin), Pulselessness, Paresthesias (tingling/numbness), Poikilothermia (cool limb), Paralysis. 2
• This condition requires intervention within hours to save the limb. 2

Spinal Cord Injury

• If you experienced any trauma (fall, motor vehicle accident, bicycle crash, diving injury) or are age 65 or older with any neck/back pain, assume spinal cord injury until proven otherwise. 4
• Tingling in extremities is a specific risk factor suggesting spinal injury. 4
• Do not move your neck—manually stabilize your head and activate emergency services immediately. 4
• A 37-year-old man with similar symptoms (numbness and weakness in hands with burning in forearms) after a ground-level fall had cervical spinal cord compression requiring urgent decompression surgery within 48 hours. 4

Emergency Department Evaluation Protocol

Immediate Testing (Within Minutes)

• Check blood glucose at bedside immediately—hypoglycemia can cause focal arm weakness mimicking stroke. 1
• Measure blood pressure in both arms to detect arterial compromise. 2
• Perform electrocardiogram to assess for atrial fibrillation or acute cardiac event. 1

Urgent Imaging (Within 24 Hours)

• Brain CT or MRI must be completed immediately to differentiate ischemic from hemorrhagic stroke, as this fundamentally changes treatment. 1, 2
• MRI with diffusion-weighted imaging is preferred to detect acute ischemic changes. 2
• CT angiography or MR angiography from aortic arch to vertex to evaluate for arterial blockages. 1, 2
• If trauma history exists, cervical spine MRI to evaluate for spinal cord compression. 4

Laboratory Tests

• Complete blood count, serum electrolytes, creatinine, and fasting blood glucose. 1
• Do not wait for laboratory results before obtaining brain imaging—imaging takes priority. 1

Non-Emergency Causes (Only After Stroke Ruled Out)

Carpal Tunnel Syndrome

• Most common nerve entrapment condition causing numbness and tingling specifically in the thumb, index, middle, and radial half of ring finger with weakness of thumb opposition when severe. 5, 6, 7
• The Durkan maneuver (firm digital pressure across the carpal tunnel) reproduces symptoms and is 64% sensitive and 83% specific for diagnosis. 5
• More common in women, people with obesity, diabetes, and those using keyboards, computer mouse, heavy machinery, or vibrating tools. 5
• Electrodiagnostic testing is over 80% sensitive and 95% specific for confirming diagnosis. 5
• Treatment includes splinting or steroid injection initially; surgical carpal tunnel release for patients not responding to conservative therapy. 5, 7

Ulnar Nerve Compression

• Causes decreased sensation of the little finger and ulnar aspect of ring finger with intrinsic hand muscle weakness. 6
• Can occur at the elbow (cubital tunnel syndrome) or wrist (ulnar tunnel syndrome). 6
• Electromyography helps differentiate from cervical radiculopathy or thoracic outlet syndrome. 6

Cervical Radiculopathy

• Nerve root compression in the neck can cause arm weakness, tingling, and pain radiating down specific dermatomal patterns. 6
• Requires cervical spine imaging and electrodiagnostic testing to confirm. 6

Dialysis Access-Related Steal Syndrome

• If you have an arteriovenous fistula (AVF) or graft for dialysis, arm weakness with coldness and tingling may indicate steal syndrome—this can progress to fingertip necrosis and gangrene if not treated urgently. 4
• Occurs in 1-4% of dialysis patients, more common with upper arm access sites. 4
• Requires immediate referral to vascular surgeon—delay can lead to catastrophic gangrene and hand amputation. 4
• Monomelic ischemic neuropathy presents with acute global muscle pain, weakness, and paradoxically warm hand with palpable pulses starting within first hour after AVF creation—requires immediate AVF closure. 4

Chemotherapy-Induced Peripheral Neuropathy

• Only relevant if you are currently receiving or recently completed chemotherapy with taxanes, platinum agents, or vinca alkaloids. 4
• Causes symmetric tingling and numbness typically starting in fingers and toes with potential weakness. 4
• Prevention strategies include cryotherapy during infusion and exercise programs. 4

Critical Action Points

Do not assume your symptoms are "too mild" to be serious—even transient arm weakness and tingling carry 10% risk of completed stroke within one week if caused by transient ischemic attack. 1

Do not wait to see if symptoms improve—time is brain tissue in stroke, and every minute of delay increases permanent disability risk. 1

Do not drive yourself to the hospital—call 9-1-1 for immediate ambulance transport to a stroke-capable emergency department. 1

If you have diabetes, smoking history, alcohol consumption, rheumatoid arthritis, or hypothyroidism, you are at higher risk for nerve entrapment syndromes, though these typically cause bilateral rather than unilateral symptoms. 6