Title: What causes numbness in the left arm and hand? - Blog | Everlywell: Home Health Testing Made Easy
Headings: What causes numbness in the left arm and hand?
What causes numbness in the left arm and hand?
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What causes tingling in the left arm?
Inadequate blood flow
Nerve injuries
Hypothyroidism
Herniated disc
Vitamin B12 deficiency
Fractures
Carpal tunnel syndrome
Cubital tunnel syndrome
Diabetic neuropathy
Multiple sclerosis
Stroke
What to do if you experience numbness or tingling in the left arm

Content: Nerve injuries
Injuries that affect the nerves in your left arm can interrupt messages from your brain and cause numbness. For instance, brachial plexus neuropathy is a type of nerve injury characterized by damage to the nerves that run down the arms from the spinal cord. Brachial plexus neuropathy can cause pain in the shoulders and arms, as well as numbness and limited movement. Contact sports, auto accidents, and other factors can result in this kind of nerve injury. Hypothyroidism
An underactive thyroid—a condition also known as hypothyroidism—can cause a number of symptoms, including numbness, tingling, and a painful “pins-and-needles” sensation that can affect the arms. Hypothyroidism results from the underproduction of thyroid hormone by the thyroid gland, and can also lead to symptoms like fatigue, cold sensitivity, weight gain, dry skin, and more. Easily test the 3 main thyroid hormones (plus thyroid antibodies) with the Everlywell at-home Thyroid Test —and conveniently access your results on our secure, online platform. Herniated disc
A herniated disc located near nerves that run through your left arm may cause your arm to tingle and feel numb. Risk factors associated with this condition include repetitive bending or twisting of the lower back, lifting heavy objects, smoking, and having a physically inactive lifestyle. Vitamin B12 deficiency
Vitamin B12 is a key nutrient that helps the nervous system function well, so it probably doesn’t come as too much of a surprise that a B12 deficiency can lead to paresthesia—a tingling feeling or numbness that typically affects the arms, hands, legs, or feet.