Numbness and tingling that lasts only a few minutes and then subsides, such as from sitting cross-legged for too long, is usually due to temporary compression of blood vessels or nerves. However, if the condition persists or worsens, it signals an abnormality in the nervous or circulatory system.

Master, Doctor Pham Thi Xuan Thu, from the Department of Internal Medicine and Musculoskeletal Disorders at Tam Anh General Hospital, Ho Chi Minh City, explained that the nervous system transmits signals from the brain to the limbs. When this system is compressed, damaged, or lacks blood supply, signals become disrupted, causing sensations of numbness, tingling like ants crawling, or loss of sensation.

Spinal and musculoskeletal conditions are among the most common causes of this issue.

Spinal degeneration often occurs at night or with weather changes. This condition causes erosion of vertebral cartilage, and enlarged bone spurs compress nerve roots. This leads to pain and numbness in the neck radiating down both arms, or pain from the lower back down both legs.

Doctor Thu examines a patient's extremities. *Photo: Tam Anh General Hospital*

Spinal stenosis is a condition where the spinal canal narrows, compressing the nerve roots passing through it, which causes continuous, prolonged numbness in the limbs.

A herniated disc commonly affects cervical and lumbar spinal discs. The condition occurs when the nucleus pulposus protrudes from the disc's fibrous outer ring, compressing spinal nerve roots, leading to numbness and tingling in the limbs, which restricts physical mobility.

Rheumatoid arthritis is a condition caused by an immune system disorder, leading to chronic inflammation of the joint synovium and damage to blood vessels supplying nerves. This damage can result in peripheral polyneuropathy or mononeuropathy. Patients often experience symmetrical numbness and tingling in both hands or both feet, which can then spread up the arms and lower legs, accompanied by muscle weakness and intense stinging sensations.

Carpal tunnel syndrome commonly affects office workers, doctors, or individuals who frequently use their wrists. Compression of the median nerve passing through the wrist leads to numbness and tingling, primarily in the thumb, index, and middle fingers.

Tarsal tunnel syndrome is similar to carpal tunnel syndrome but occurs at the inner ankle, causing numbness and sharp pain in the sole of the foot.

Beyond musculoskeletal conditions, prolonged limb numbness can also result from metabolic and peripheral neurological diseases, vascular diseases, and cardiovascular risks.

Doctor Thu noted that many people tend to downplay or even neglect treating limb numbness. However, prolonged numbness can cause pain, restless sleep, and difficulty walking and grasping. More severely, it can lead to incontinence, muscle atrophy, and limb paralysis.

Cases of limb numbness caused by tumors or cancer compressing nerves, if not detected and treated early, can be life-threatening. Therefore, patients should seek medical attention if limb numbness persists continuously for over 6 weeks, is accompanied by changes in limb color and temperature, dizziness, memory loss, headaches, or shortness of breath.

Depending on the specific cause of limb numbness, doctors prescribe different treatment methods. Additionally, to alleviate discomforting symptoms, patients can perform exercises or gentle massages to improve blood circulation, apply warm compresses to relax muscles and enhance blood flow, and apply cold compresses if there is joint swelling or inflammation. It is also important to avoid overexertion or incorrect postures like prolonged sitting, squatting, or heavy lifting.

Phi Hong