Whenever a patient asks me with a sincere expression: “Doctor, my feet are numb, is it impassable for blood?” I can only smile to answer…because there is no such term as impassable blood in modern medicine. , The reason for the numbness of the feet can be attributed to two major problems: vascular disorders or neurological disorders. After all, what are the problems that make our feet numb?

First, the blood path is blocked due to “vascular disorders”

◆Diabetes: In the field of foot and ankle specialists, the most common symptoms of foot numbness caused by blood vessel problems are diabetic patients. Because diabetic patients are very prone to poor blood sugar control, like lack of rain in the desert, causing microvascular disease and feeling numb.

Diabetes promotes the aging of blood vessels and causes arteriosclerosis. Fat is mixed with smooth cells and calcium to accumulate on the inner walls of blood vessels, causing cardiovascular diseases and peripheral vascular symptoms such as intermittent claudication, foot ulcers, and other diseases. To delay the deterioration of the condition, it is necessary to actively control blood sugar, treat hyperlipidemia, quit smoking, control diet, and do more foot exercises to prevent foot injuries.

◆Arteriosclerosis: Although there is a small chance that patients will block their feet due to three high problems (hypertension, hyperlipidemia, and hyperglycemia), the possibility of “foot stroke” still exists. There are also cases where trauma caused “acute arterial obstruction”. At this time, it is necessary to try to unclog the arteries within the golden eight hours. Once missed, the foot tissues will be necrotic and face the pain of amputation.

◆Venous thrombosis: The most common is deep vein obstruction, which is often referred to as “economy class syndrome.” Because the legs cannot be stretched and flexed because of sitting for a long time, it is easy to cause deep vein thrombosis. In mild symptoms, lower extremity edema occurs, in severe cases. This is because these clots will run along with the bloodstream to the lungs, blocking the blood vessels in the lungs and causing a pulmonary embolism, causing breathing difficulties, even strokes or death. However, the perception of these symptoms is different, and it is more of a feeling of “foot swelling” rather than “feet numbness.”

Second, blood circulation caused by “neurological disorders”

In addition to the problem of foot numbness caused by vascular disorders, the nervous system controls the body’s perception. Of course, it is more closely related to this symptom. From the point of view of the nervous system, there are two types:

◆Central Nervous System
The central nervous system is composed of the brain and spinal cord, so the most common symptoms of foot numbness include “intervertebral disc herniation” and “spinal stenosis”. Once it is confirmed that the cause of the patient’s foot numbness is caused by central nervous system disorders, They will be referred to spine surgery for symptomatic treatment by professional doctors.

◆ Peripheral nervous system

This type of neurological disorder presents a very different situation:
● Peripheral neuropathy of diabetic foot: This condition is relatively incurable. It is a holistic medical disease. You can only control your blood sugar by yourself and check back regularly.
●Tarsal Tunnel Syndrome (Tarsal Tunnel Syndrome): This is a field of foot and ankle specialists. Many people don’t know it deeply, and it is easy to be misdiagnosed as plantar fasciitis or plantar pain. I have read the experience of a patient in the United States on the Internet. This patient originally had pain and discomfort in the foot disc. He was diagnosed with plantar fasciitis by an orthopedic doctor. The steroid treatment was ineffective. Another orthopedist told me. He is simply tired or inflamed. It took more than ten months for this man to find out that the problem was “tarsal tunnel syndrome.” After the operation, he recovered and his feet were no longer numb.

Seeing this man’s sharing made me very emotional: Just imagine that in the medically advanced United States, it takes so long to find out the real cause and prescribe the right remedy. Not to mention that in Taiwan, everyone’s understanding of the ankle is still in place. In the chaotic state, I believe that the rate of misdiagnosis of such patients will be higher. There must be many patients who have been wandering for a long time, and the correct problem has not been diagnosed so far. So I want to share some ideas with you in this part.

The principle of tarsal tunnel syndrome is that when the tibia nerve passes through the inner side of the ankle joint to the foot, there is a tubular channel that often blocks nerve conduction due to trauma, swelling, tumor compression, or natural constitution. At this time, the patient will feel foot numbness. The key is that the location of numbness will only occur on the bottom of the foot and the inner side of the foot disc and other distal nerves. The location is very clear, and there will be no numbness in the thighs and calves.

In addition, if the patient has a sensation similar to the electric current passing through the place where the tibial nerve passes by lightly tapping on the lower part of the medial ankle joint, it may be “tarsal tunnel syndrome”.

On the whole, many of the problems with ancillary duct syndrome are primary and no cause can be found. However, it may also cause fibrosis or swelling in the tarsal duct due to injury; or tophi just grows there and is crushed; or It is the ganglion cyst that just grows in the area and is compressed; or because of the heel bone healing, the medial and posterior side protrudes and then presses into the tarsal tube; even because of the flat feet…, it is necessary to explore the real cause of its occurrence.

I want to emphasize that tarsal tunnel syndrome can be treated with nerve decompression by surgery. The main key is whether the problem can be correctly diagnosed. If it is only a short-term swelling, sometimes it can be improved without surgery.