The term 'numbness' literally means inability to feel the touch on the superficial skin. Left side of the face becoming numb is indicating that something is wrong with the facial nerve. As we all know, the facial nerve is connected to the brainstem (an important component of the brain) that are known to control the sensation of touch. So, whenever any object makes a physical contact with the face, the facial nerve transports this sensation to the specific part of the brain where it is interpreted as a pain or a pressure. However, when this facial nerve is not working properly, one is bound to expect numbness on either left or right side of the face. In other words, dysfunction of the facial nerve can make the left side of the face insensitive to touch. It is elaborated below:
This condition is typically marked by tingling in face, followed by facial numbness. The trigeminal nerve emerging from the brainstem is said to provide facial numbness. Three nerves branch out from the trigeminal nerve and then enter the facial area by taking different routes. If any of these nerves are subjected to compression or are damaged, it may trigger unusual sensations on the face. Complications in diabetes or those suffering from slip disc or hyperventilation syndrome may experience facial paresthesia.
The facial nerve transmits electric signals to and from the brain in order to control facial muscles. Thus, actions like smile, that involve movement of facial muscles, are initiated by the facial nerve. In Bell's Palsy, the facial nerve has no control over muscles located on one side of the face. This happens because the nerve gets inflamed, due to a viral infection of herpes zoster. Although, herpes zoster can affect any nerve in the body, when it strikes the facial nerve, the condition is referred to as Ramsay Hunt syndrome. Also referred as facial paralysis, the condition is typically marked by formation of fluid-filled blisters near the ear.
In a stroke, blood supply to a specific area in the brain is either completely blocked or inadequate. These disturbances in the blood circulation can interfere with the electrical activity of the brain. This can give rise to tingling and numbness in any part of the body including the face. Even after the stroke subsides, the numbness may not go away for quite some time.
Multiple scelerosis (MS) is a condition that brings about irreparable damage to the nerves. The myelin sheath seen enveloping the nerves gets damaged in patients suffering from multiple scelerosis. The myelin sheath, made up of protein and fat acts like a protective covering for the nerve and does an excellent job of facilitating the electrical impulses. However, with the myelin sheath getting eroded, signal transmission through the nerves can become extremely slow and even stop completely. In case, MS affects the facial nerve, one may experience numbness on any side of the face. Multiple scelerosis is believed to be an autoimmune disorder in which the defense mechanism of our body is responsible for destroying the myelin sheath.
Chemotherapy drugs used in the treatment of cancer can also cause facial numbness on either side. Apart from these cancer drugs, other factors responsible for causing numbness on the face are exposure to toxic metals and excess intake of vitamin B6 supplements.
If the tissues, muscles or bones are exerting too much pressure on the nerves that are in close proximity, it can cause loss of sensation in the affected area. So, in case the facial nerve is subjected to excessive pressure from surrounding tissues, numbness on the face is the likely outcome.
Sinus trouble can also make the left side of the face numb. The bones situated in the facial area contain hollow cavities, which are nothing but sinuses. The nasal passages and the sinuses are interconnected, and so when we inhale through the nose, sinuses prevent dust particles from reaching the airways and the lungs. The sinuses produce mucus, which helps them to trap air contaminants. A bacterial or a viral infection of the sinus can lead to excess production of mucus, thereby causing breathing problems. The resulting discomfort arising from blocked and swollen sinuses is known as sinus pressure, which can give a feeling of tingling and numbness on right or left side of the face. Even people diagnosed with common cold may experience these abnormal sensations on the face.
As aforementioned, the trigeminal nerve arising from the brainstem has 3 different nerve branches and one of them make its way through the inner jawbone. Now, the wisdom teeth are very near to this jawbone and so during their extraction, nerve damage may occur. This injury to nerve can also cause facial paresthesia. People with swollen wisdom tooth might face the same abnormal sensation associated with facial paresthesia.
Treatment depends upon the underlying cause. Nerve-related disorders like Bell's palsy that are caused from herpes zoster infection are treated with antiviral drugs. On the other hand, anti-inflammatory drugs like ibuprofen may help to relieve discomfort related to altered nerve function.
Massaging the area with aromatic oils and specific ointments may also relieve the compression on the nerve, thereby helping to improve the symptoms. Many times, paresthesia has been linked to vitamin B12 deficiency. So, taking the necessary supplements in the required dosage may help to manage paresthesia. Alcohol consumption also has to be avoided, as it can worsen paresthesia symptoms.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.