I’hypoaesthesia is a term of medical language. We speak more commonly ofnumbness.

Hypoesthesia refers to the decreased sense of touch. This term comes from the Greek prefix low (under) and suffix aesthesia (sensitivity).

Hypoesthesia is common and can affect any part of the body (both the legs and the arms or even the extremities such as the hands, feet or even the face).

Hypoesthesia can be the consequence of aging, prolonged poor posture, a blood circulation disorder or damage to the nervous system linked to disease, mechanical compression, stroke or intoxication.

Hypoesthesia is diagnosed by a simple physical examination or by a test using sharp needles inserted into the skin or threads placed on the skin.

It is necessary to differentiate hypoesthesia from other touch sensitivity disorders:

• Anesthesia which designates a total loss of sensitivity;
• paresthesia which corresponds to the tingling sensation;
• Dysesthesia which is defined by an alteration of sensations. This symptom is described as unpleasant;
• Hyperesthesia or the perception of heightened sensations;
• somesthesia refers to a set of different sensations (pressure, heat, pain, etc.) that come from several regions of the body (skin, tendons, joints, viscera, etc.).

Hypoesthesia may be the consequence of a central or peripheral nervous system dysfunction which can result:

• Of aging (since with age, the sensors, of the mechano-receptor type, lose sensitivity, and become less numerous).
• of a Guillan-Barré syndrome.
• of a neurodegenerative disease (Alzheimer’s diseasethere Parkinson disease and the multiple sclerosis).

• of a nerve compression in case of tumors or of herniated disc.

• of a trauma or some metastases affecting the spinal cord.

• certain infections such as HIV or the Meadow.

• of a alcohol, toxic agent, or drug intoxication (for example heavy metals, certain chemotherapy drugs, etc.). chronic alcoholism may cause loss of sensitivity.

• Of metabolic disorders causing neuropathy: diabetes, chronic renal failure, thiamine or vitamin B12 deficiency.

• A inflammation of the spinal cord like a transverse myelitis.

• A inflammatory disease Or autoimmune (as the systemic lupus erythematosus).
• A neuralgia (nerve pain) like a trigeminal nerve facial neuralgia.

Hypoesthesia can sometimes affect the lower limbs. It can be bilateral or unilateral (affecting both or one leg(s)). It can then be associated with a feeling of heaviness and/or tingling in the leg. It can be the consequence of one of the causes mentioned above or of:

• A restless leg syndrome ;
• A blood circulation disorder like a venous insufficiency ;
• a extended leg position – such as crossed or bent legs – causing compression of a nerve or one or more blood vessels;
• a sciatic nerve compression (common cause of pain in the buttocks region).

It happens to lose the sense of touch in the arm. Some causes are specific to the numbness of this part of the body such as:

• THE carpal tunnel syndrome which leads to sensory and motor problems in the first three fingers of the hand, caused by compression of the wrist nerve.
• of the thyroid disorders can also numb the upper limbs.
• A osteoarthritis of the wrist.
• A neck pain which can extend to the arms and cause these symptoms to appear.
• The fact of sleep on his arm which leads to nerve compression.
• A cerebrovascular accident : Arm numbness is a specific sign of ischemic stroke, which is a medical emergency (every minute counts).

Patients with hypoesthesia may describe:

• a insensitivity to pain ;
• a difficulty feeling hot and cold ;
• a insensitivity to touch ;
• a numbness.

These symptoms may be accompanied by other signs depending on the associated disease, such as:

• of the tingling Or tingling (paraesthesia);
• of pains especially in cases of nerve compression such as sciatica or facial neuralgia (pain on one side of the face);
• a fatigue ;
• a muscular weakness ;
• a crisis ofmigraine or severe headache;
• a loss of vision ;
• of the speech disorders …

Hypoesthesia has several consequences. It can lead to:

• a difficulty walking or driving when it affects the legs;
• of the more frequent falls and loss of balance;
• of the risk of serious injury(s) or burn(s) (since the patient does not feel pain);
• the risk of complication(s) and a delay in treatment in the event of a skin infection (abscess, erysipelas, diabetic foot ulcers …).

In the majority of cases, hypoesthesia is transient and resolves spontaneously.

Nevertheless, it is preferable to consult a doctor if the loss of sensitivity is accompanied by loss of muscle tone or strength.

It is strongly recommended to contact 15 or 112 or to go directly to the emergency department if the loss of sensitivity occurs suddenly, affects one side of the body, particularly in the arm, persists for more than five minutes or if it accompanied by a state of confusion.

In any case, it is better to avoid self-medication, in particular taking non-steroidal anti-inflammatory drugs (NSAIDs) without medical advice.

To diagnose hypoesthesia, the doctor must carry out a clinical examination and an interrogation of the patient. He may possibly prescribe additional examinations to find out the cause of this symptom: medical imaging (Brain MRIin particular) or even blood tests or a electromyogram.

Treatment varies greatly depending on the cause. A diabetic will for example have to maintain medical monitoring (in endocrinology and nutrition) and monitor his blood sugar level. An alcoholic will have to endure alcohol withdrawal. In the event of a stroke, drugs are given to dissolve the clot that is blocking the blood vessel. The treatment can be surgical, to empty the pocket of blood which compresses part of the brain. Certain medications may be prescribed in case of facial neuralgia (anticonvulsants, antispasmodics, antidepressants and anxiolytics…).