Numbness of the hands in medical terms is called paresthesia. Paresthesia is a term used to describe an unpleasant sensation of tingling, burning, stinging, numbness or cold in the skin that can be caused by polyneuropathies, spinal disorders, metabolic diseases or vitamin deficiencies. Depending on the intensity, extent and duration of the paresthesia, they can have multiple etiologies and can determine different degrees of impact on the patient’s quality of life.
Hand numbness due to orthopedic causes
Numbness of the hands due to neurological causes
How are paresthesias manifested in the upper limb?
Hand numbness due to orthopedic causes
Tingling or numbness of the upper limbs can represent benign manifestations with self-limiting evolution that are caused by prolonged pressure applied to certain nerve endings. The compression of the peripheral nerves that serve the upper limb is frequently favored by vicious positions adopted during sleep or during daily activities that involve working at the computer, with the prolonged use of the mouse.
Paresthesia located in the upper limb can also be due to the compression of a peripheral nerve in certain specific places, on a hard bony or tendinous plane during professional activities (handwriting, painting). Most frequently, upper limb paresthesia occurs as a result of compression of the median nerve at the level of the carpal tunnel and of the ulnar nerve in the elbow region.
Another cause of paresthesia of the upper limb is represented by the compression of the nerve roots at the level of the cervical spine (traumas, fractures), the manifestations being accompanied in this situation by pain along the affected nerve path.
Numbness of the hands due to neurological causes
Tingling in the hands of increased intensity and duration, which are accompanied by pain, weakness and muscle atrophy, can be determined by neural damage of various etiologies, which vary from viral infections – HIV or bacterial infections – syphilis and exposure to toxic substances, up to vitamin B12 deficiency or metabolic disorders – type 2 diabetes associated with peripheral neuropathy.
Vitamins E, B1, B6, B12 and niacin are essential for the proper functioning of the peripheral nerves. The deficiency of these vitamins favors the appearance of pernicious anemia, which is associated, along with other manifestations, with paresthesia in the upper and/or lower limbs. Chronic alcohol consumption is another risk factor predisposing to the appearance of upper limb paresthesia, a condition known as alcoholic neuropathy.
Hyperventilation syndrome represents an increase in respiratory rate and can cause paresthesia in the upper limb as a result of metabolic imbalances that affect the nerve fibers at this level. Hyperventilation that causes tingling in the hands is frequently found in people who have panic attacks.
Poisoning with heavy metals such as mercury, along with multiple sclerosis, transverse myelitis, viral or bacterial encephalitis, arteriovenous malformations or brain tumors are other pathologies that can cause paresthesia in the upper limbs in their evolution.
Numbness of the hands due to cardiovascular causes
Transient ischemic attack (TIA) is a cause of paresthesia of the upper limb and is due to a temporary, reversible cerebral hypoperfusion that completely resolves without the appearance of permanent motor and sensory deficits.
Acute myocardial infarction frequently causes the appearance of paresthesia accompanied by pain in the upper limb, which may radiate to the shoulder, submandibular or interscapular area.
Systemic vasculitis or those secondary to connective tissue pathologies, tumors or infections, represent conditions that frequently cause the appearance of paresthesia in the upper and/or lower limbs by affecting the peripheral nervous system.
How are paresthesia manifested in the upper limb?
Paresthesia of the upper limb is described by patients in the form of tingling, stinging, cold sensation or throbbing pain. Numbness of the hands can sometimes be accompanied by muscle spasms, erythema, sensitivity to touch or functional impotence of the affected limb.
The diagnosis of paresthesia of the hand
The diagnostic evaluation of paresthesia of the upper limbs requires a thorough clinical examination of the patient, accompanied by anamnestic data that will orient the specialist to the etiology that determines the appearance of tingling.
The clinical examination can reveal the presence of radiculopathy due to a collapse of the spinal canal (spinal stenosis) at the cervical level, with a decrease in muscle strength, sensitivity and reflexes in the upper limb affected by paresthesia.
People previously diagnosed with diabetes have bilateral manifestations in the upper and/or lower limbs represented by the loss of sensitivity to pain, touch, temperature, vibrations and proprioception, specific symptoms of diabetic neuropathy.
In certain situations, the detailed physical examination can reveal specific manifestations of Guillan Barre syndrome or multiple sclerosis depending on each case.
Depending on the information obtained, the specialist doctor will request additional investigations to confirm the diagnosis. Laboratory analyses deny or confirm the presence of low levels of vitamin B12, hyperglycemic values or the presence of a high titer of antinuclear antibodies, these results confirming various etiologies involved in the appearance of upper limb paresthesia. Investigations that involve the collection of cerebrospinal fluid through lumbar puncture are useful for detecting cases of bacterial or viral encephalitis that cause paresthesia.
Electromyography and nerve conduction tests can exclude a diagnosis of nerve dysfunction while imaging investigations such as MRI and CT are used to establish the diagnosis of multiple sclerosis or stroke that evolves with limb paresthesia.
Treatment of numb hands
The treatment of paresthesia of the upper limbs is etiological and addresses the cause that determines the appearance of numbness in the hands.
Vicious postures that cause the pinching of various nerve threads with the appearance of numbness of the hand can be improved by light stretching exercises and massage of the affected limb.
In the case of paresthesia which is associated with metabolic diseases with chronic evolution, such as type 2 diabetes, it is recommended to keep glycemic values under control and take non-steroidal anti-inflammatory drugs to relieve the pain that accompanies the feeling of numbness in diabetic neuropathy.
Patients with severe paresthesia benefit in certain situations from treatment with antidepressant preparations through which the patient’s degree of perception of the pain that accompanies tingling is reduced. Severe avitaminoses that cause the manifestation of tingling in the hand are treated with the help of vitamin B complex supplements, especially vitamin B12.
Bacterial and viral encephalitis are treated with specific antibacterial and antiviral medication along with anti-inflammatory, depending on each case.
Autoimmune diseases that evolve in association with the presence of paresthesia are treated with the help of corticosteroid medication, which aims to reduce the exacerbated response generated by the immune system.
Nerve compressions at the level of the cervical spine can in certain situations benefit from surgical intervention to correct displaced bone structures or fractures that damage the nerve threads that serve the upper limbs.
Do not postpone the medical consultation in case of disturbing symptomatology. The prevention and detection of medical conditions in the early stages means high chances of healing, low costs, and reduced risks 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
