Causes

Numbness is caused by damage, irritation or compression of nerves. A single nerve branch or several nerves may be affected, as with a slipped disk in the back or carpal tunnel syndrome in the wrist. Certain diseases such as diabetes, or toxins such as chemotherapy drugs or alcohol, can damage the longer, more-sensitive nerve fibers (such as those going to your feet) and cause numbness.

Numbness commonly affects nerves outside of the brain and spinal cord, usually causing a lack of sensation in the arms, legs, hands and feet.

Numbness alone, or numbness associated with pain or other unpleasant sensations, isn't usually due to life-threatening disorders such as strokes or tumors.

Your doctor will need detailed information about your symptoms to diagnose the cause of your numbness. A variety of tests may be needed to confirm the cause before appropriate treatment can begin.

Possible causes of numbness in one or both of your hands include:

Brain and nervous system conditions

• Acoustic neuroma
• Brain aneurysm
• Brain AVM (arteriovenous malformation)
• Brain tumor
• Guillain-Barre syndrome
• Herniated disk
• Paraneoplastic syndromes of the nervous system
• Peripheral nerve injuries
• Peripheral neuropathy
• Spinal cord injury
• Spinal cord tumor
• Stroke
• Transient ischemic attack (TIA)
• Transverse myelitis

Trauma or overuse injuries

• Brachial plexus injury
• Carpal tunnel syndrome
• Frostbite

Chronic conditions

• Alcohol use disorder
• Amyloidosis
• Charcot-Marie-Tooth disease
• Diabetes
• Fabry's disease
• Multiple sclerosis
• Porphyria
• Raynaud's disease
• Sjogren's syndrome

Infectious diseases

• Leprosy
• Lyme disease
• Shingles
• Syphilis

Treatment side effects

• Side effects of chemotherapy or anti-HIV drugs

Other causes

• Heavy metal exposure
• Thoracic aortic aneurysm
• Vasculitis
• Vitamin B-12 deficiency