Hand numbness in medical terms is called paresthesia. Paresthesia is a term used to describe an unpleasant tingling, burning, stinging, numbness or cold sensation in the skin that may be caused by polyneuropathy, spinal conditions, metabolic diseases or vitamin deficiencies. Depending on the intensity, extent and duration of the paresthesia, it can have multiple aetiologies and can result in varying degrees of impairment of the patient’s quality of life.
Hand numbness from orthopaedic causes
Hand numbness due to neurological causes
Hand numbness from cardiovascular causes
How does paresthesia manifest itself in the upper limb?
Hand numbness from orthopedic causes
Tingling or numbness of the upper limbs may be benign manifestations with a self-limiting course that are caused by prolonged pressure applied to certain nerve endings. Compression of the peripheral nerves serving the upper limb is frequently favored by vicious positions adopted during sleep or daily activities involving computer work with prolonged use of the mouse.
Paresthesias located in the upper limb may also be due to the compression of a peripheral nerve in specific places, on a bony or tendon-hard surface during professional activities (handwriting, painting). Most commonly, upper limb paresthesias occur as a result of compression of the median nerve at the carpal tunnel and the ulnar nerve in the elbow region.
Another cause of upper limb paresthesia is compression of nerve roots in the cervical spine (trauma, fractures), in which case the symptoms are accompanied by pain along the affected nerve pathway.
Hand numbness due to neurological causes
Hand tingling of increased intensity and duration accompanied by pain, weakness and muscle atrophy may be caused by neuronal damage of various etiologies, ranging from viral infections – HIV or bacterial infections – syphilis and exposure to toxic substances to vitamin B12 deficiency or metabolic disorders – type 2 diabetes mellitus associated with peripheral neuropathy.
Vitamins E, B1, B6, B12 and niacin are essential for the proper functioning of peripheral nerves. Deficiency of these vitamins favors the appearance of pernicious anemia, which, along with other manifestations, is associated with paresthesia in the upper and/or lower limbs.
Chronic alcohol consumption is another risk factor predisposing to the development of paresthesia of the upper limbs, a condition known as alcoholic neuropathy.
Hyperventilation syndrome is an increase in respiratory rate and can lead to upper limb paresthesia as a result of metabolic imbalances affecting the nerve fibers in the upper limb. Hyperventilation, which causes tingling in the hands, is frequently seen in patients with panic attacks.
Heavy metal poisoning such as mercury, along with multiple sclerosis, transverse myelitis, viral or bacterial encephalitis, arteriovenous malformations or brain tumors are other pathologies that can cause the development of paresthesias in the upper limbs.
Hand numbness from cardiovascular causes
Transient ischemic attack (TIA) is a cause of upper limb paresthesia and is due to a temporary, reversible cerebral hypoperfusion that fully remits without permanent motor and sensory deficits.
Acute myocardial infarction frequently causes paresthesia accompanied by pain in the upper limb, which may radiate to the shoulder, submandibular or interscapular.
Systemic vasculitis or vasculitis secondary to connective tissue pathologies, tumors or infections, are conditions that frequently cause paresthesia of the upper and/or lower limbs by affecting the peripheral nervous system.
How does paresthesia manifest itself in the upper limb?
Upper limb paresthesia is described by patients as tingling, prickling, cold or shooting pain. Hand numbness may sometimes be accompanied by muscle spasms, erythema, tenderness to touch or functional impotence of the affected limb.
Diagnosis of hand paresthesia
The diagnostic evaluation of paresthesia of the upper limbs requires a thorough clinical examination of the patient, accompanied by anamnestic data to guide the specialist to the etiology causing the tingling.
The clinical examination may detect the presence of radiculopathy due to a collapsed spinal canal (spinal stenosis) at the cervical level, with decreased muscle strength, sensitivity and reflexes in the upper limb affected by paresthesias.
People with a previous diagnosis of diabetes have bilateral upper and/or lower limb manifestations of loss of sensitivity to pain, touch, temperature, vibration and proprioception, symptoms specific to diabetic neuropathy.
In certain situations, a thorough physical examination may detect specific manifestations of Guillan Barre syndrome or multiple sclerosis on a case-by-case basis.
Depending on the information obtained, the specialist will request further investigations to confirm the diagnosis. Laboratory tests will either refute or confirm the presence of low vitamin B12 levels, hyperglycaemic values or the presence of high antinuclear antibodies, confirming various aetiologies involved in the development of upper limb paresthesia. Investigations involving the collection of cerebrospinal fluid by lumbar puncture are useful for detecting cases of bacterial or viral encephalitis that cause paresthesia.
Electromyography and nerve conduction tests can rule out a diagnosis of nerve dysfunction while imaging investigations such as MRI and CT are used to establish the diagnosis of multiple sclerosis or stroke evolving with paresthesias of the limbs.
Treatment of numb hands
The treatment of upper limb paresthesia is aetiological and addresses the cause of numbness in the hands.
Vicious postures that cause the various nerve threads to become pinched, resulting in numbness of the hand, can be relieved by gentle stretching and massage of the affected limb.
In the case of paresthesias that are associated with chronically progressive metabolic diseases such as type 2 diabetes mellitus, it is recommended to keep blood glucose levels under control and to take non-steroidal anti-inflammatory drugs to relieve the pain that accompanies the numbness in diabetic neuropathy.
Patients with severe paresthesia benefit in certain situations from treatment with antidepressant preparations which reduce the patient’s perception of the pain accompanying the tingling. Severe avitaminosis which causes tingling in the hand is treated with vitamin B complex supplements, especially vitamin B12.
Bacterial and viral encephalitis are treated with specific antibacterial and antiviral medication along with anti-inflammatory medication, depending on the individual case.
Autoimmune diseases that are associated with the presence of paresthesia are treated with corticosteroid medication to decrease the exacerbated response generated by the immune system.
Nerve compression in the cervical spine may benefit in certain situations from surgery to correct displaced bone structures or fractures that injure the nerve pathways serving the upper limbs.
Do not delay medical consultation if distressing symptoms occur. Prevention and early detection of medical conditions means high chances of cure, low costs, reduced risk of disease exacerbation and complications.
References:
- An outpatient with hand numbness: old prejudices, new strategies of differential diagnosis and treatment, Magomedova A.M., Merkulov Y.A., Biglova A.N., Smolentseva K.V., Merkulova D.M. – https://europepmc.org/article/med/31089090
- Common Hand Conditions A Review, Kelly Bettina Currie, Kashyap Komarraju Tadisina, Susan E. Mackinnon – https://jamanetwork.com/journals/jama/article-abstract/2793654
- Numbness in hands, Mayo Clinic – https://www.mayoclinic.org/symptoms/numbness-in-hands/basics/causes/sym-20050842
