Paresthesia is the sensation of tingling or other abnormality (tingling, numbness…) in some part of the body. This can occur in the hands, for example.
This is quite common. But why is it happening? Is it serious? Depends on the case.
In this article we will know 9 possible causes that explain the numbness of the handsAs we shall see, sometimes there is an underlying disease that explains it.
My hands are falling asleep: what can it be due to?
Just like that, numbness or tingling or tingling sensation in the hands (paresthesia) is a very common symptom. Normally it is something momentary and it does not have major importance, although we will have to analyze in each case what possible causes originate this symptom (since sometimes it is a symptom of alert of certain diseases).
Paresthesia in the hands appears due to an alteration in our sensibility “by excess”; that is to say, we experience an abnormal sensation in a determined zone of the body, without any stimulus that causes or explains it.
Paresthesia may appear in the context of an underlying medical condition (as a cause or consequence of it) or in isolation (in healthy people, who have simply long maintained a posture, or other situations).
Let’s look at 9 possible causes that could explain the numbing sensation in the hands.
1. Stay in the same posture
A very frequent cause of numbness in the hands is the maintenance of the same posture for a long time.
2. Sleeping with the hand “squeezed” on the pillow
Another possible cause of numbness in the hands is having slept with the hand under the pillow or between the legs, so that was trapped. It can be a nap during the day or at night.
3. Nutritional deficit
A nutritional deficit could also explain the numbing sensation we have in our hands. Thus, this lack of certain nutrients could be the cause (e.g. deficits in vitamin B, vitamin B12, folic acid, etc.).
4. Compressed nerve
If a nerve in your hand or arm has been compressed, you may also experience this numbness in your hand or arm. There are different nerves that, when compressed, cause this numbness. Depending on the area, it will be one pathology or another. Let’s see the different possibilities:
Carpal tunnel syndrome
This syndrome is caused when the median nerve of the wrist becomes trapped. Specifically, the carpal tunnel is a channel that goes from the palm of the hand to the bones of the wrist, through it pass the tendons (so that we bend the fingers) and the median nerve.
When this syndrome appears, other symptoms appear that accompany it, beyond the numbness of the hand (or hands), such as: weakness of the wrist, difficulties in making some movements or picking up objects, as well as pain in the wrist and forearm (this pain may also increase during the night).
4.2. Disc herniation
We may also have a herniated disk. To understand what it is, let’s imagine our spine; between each of its vertebrae we find a disc that protects them and acts as a shock absorber.
When the nucleus of some of these discs goes outwards (due to wear, injury, etc.), what we call disc herniation occurs. If a herniated disk occurs in the neck, numbness (or tingling) may appear in the hands.
4.3. Guyon canal syndrome
Another syndrome that could originate a compressed nerve is Guyon Canal Syndrome, which could also be the cause of our numbness of hands. In this case, compression of the nerve occurs in the area of the elbow (in a nerve called the ulnar).
This syndrome is also accompanied by other symptoms, such as pain in the elbow area (which may extend to the hand), muscle weakness in the hand, difficulties in performing the gesture of the “clamp” with the fingers, difficulties in flexing the fingers and the so-called claw hand (which is when the fingers remain bent and cannot be stretched).
5. Endocrine disease
The numbness or tingling sensation of the hands may also be indicating the possibility of endocrine disease. Endocrine diseases have to do with the hormone levels in our body. Let’s look at the two most common endocrine diseases that could be the cause of this abnormal sensation in the hands:
People who have diabetes are more likely to have some type of nerve damage (especially when blood glucose control is altered or disrupted). Nerves influence the sensitivity of the extremities, which is why diabetics may experience more often a numbness in the hands (or tingling, tingling, etc.).
Thus, although these damages tend to have a special effect on the lower extremities, they can also appear on the upper extremities. Specifically, diabetic neuropathy is a type of nerve damage caused by diabetes. This affectation is suffered by about 50% of patients with diabetes (after 20 years with the disease).
Hypothyroidism is another endocrine disease that may also be the cause of numbness of the hands. This numbness can also affect the arms. In this way, hypothyroidism can lead to nerve endings being affected.
But what is hypothyroidism? This is an alteration in the secretion of thyroid hormone (related to stress), that is, the thyroid gland, responsible for secreting it, produces it in lower quantities than normal.
Hypothyroidism affects the body’s normal metabolism and can also cause depressive symptoms, excessive tiredness, concentration difficulties, cold sensation, weight gain, etc…
6. Circulatory or cardiovascular alterations
Another underlying cause of hand numbness is circulatory or cardiovascular disease. Normally, when there is an alteration, problem or basic circulatory disease, the symptom of numbness of the hands is accompanied by others such as changes in the color of our skin.
Thus, in this case, the numbing sensation of the hands is caused by an alteration in the blood flow of our vessels, which contract or dilate in an altered or unusual way.
On the other hand, when the cause is a problem or cardiovascular disease, the explanation lies in the fact that a correct blood flow does not take place in certain areas of the body (such as the hands), due to the accumulation of plaques in the arteries (atherosclerosis).
Brenta, G. (2006). Hypothyroidism and the cardiovascular system. Rev Fed Arg Cardiol.
Olmos, P., Niklitschek, S., Olmos, R., Faúndez, J., Quezada, T., Bozinovic, M., Niklitschek, I., Acosta, J., Valencia, C. and Bravo, F. (2012). Physiopathological bases for a classification of diabetic neuropathy. Revista médica de Chile, 140(2): 1593-1605.
Portillo, R., Salazar, M. and Huertas, M.A. (2004). carpal tunnel syndrome. Clinical and neurophysiological correlation. Medical School Annals, 65(4).