Numbness and Tingling in Hands and Feet

Numbness and tingling can have many causes. It may be temporary, such as after sleeping on an arm, or may continue when a nerve is compressed, damaged or affected by an underlying condition.

• Nerve compression: Sleeping in an awkward position, repetitive movements or an injury can put pressure on a nerve and cause numbness or a pins-and-needles sensation. Conditions such as carpal tunnel syndrome can also cause persistent symptoms in specific areas of the hand. Numbness in specific fingers, the hand, or part of the foot may sometimes indicate which nerve is affected.
• Diabetes: Diabetes is a common cause of peripheral nerve damage. Tingling often begins in the feet and may gradually move upwards into the legs. The hands may become affected later. In some people, numbness or altered sensation may be noticed before diabetes has been diagnosed.
• Vitamin deficiencies: Certain vitamins and minerals are important for healthy nerve function. Deficiency of vitamin B12, for example, can cause numbness and tingling. At the same time, supplements should not be taken without identifying an actual deficiency, as excessive intake of some vitamins can also cause nerve symptoms.
• Spinal and nerve problems: Problems in the neck or lower back can affect the nerves travelling to the arms or legs. Cervical spondylosis, slipped or herniated discs and sciatica are some conditions that can produce tingling or numbness along a particular nerve pathway.
• Injuries: A nerve may be compressed, stretched or damaged following an accident, fall, sports injury or surgery. Repeated pressure on a particular area can also cause nerve symptoms.
• Thyroid, kidney and liver disorders: Certain systemic conditions can affect nerve function. An underactive thyroid, kidney disease and liver disorders are among the conditions that may be associated with peripheral neuropathy.
• Alcohol and toxins: Excessive alcohol use can affect nerves directly and may also contribute to nutritional deficiencies. Exposure to heavy metals and certain industrial chemicals can also damage peripheral nerves.
• Medicines: Some medicines, particularly certain drugs used in cancer treatment, can cause peripheral nerve symptoms. A complete medication history is therefore an important part of the assessment.
• Infections and autoimmune conditions: Numbness or tingling can sometimes develop after an infection such as shingles, hepatitis B or C, or HIV. Autoimmune conditions, including lupus, rheumatoid arthritis and Guillain-Barré syndrome, can also affect the nerves.
• Stress and anxiety: A period of intense stress or anxiety can bring on tingling, sometimes in the hands and feet and sometimes around the mouth or face. However, persistent numbness should not automatically be attributed to stress without proper evaluation.

Supti is primarily understood in relation to disturbed Vata. Classical descriptions also recognise the roles of Kapha and Rakta in certain presentations. Vyana Vayu, a subtype of Vata, has an important role in circulation and sensory functions. When its normal activity is disturbed or obstructed, altered sensation may occur.

Acharya Sushruta describes Padaharsha, in which tingling and numbness of the feet are associated with the involvement of Vata and Kapha. Classical texts also describe Supti in relation to Twakgata Vata, where disturbed Vata affects the skin and sensation. Similar descriptions of altered sensation are found in conditions such as Raktavrita Vata, Vatarakta and Vyanavrita Prana, where the normal functioning of Vata is affected by obstruction or association with other factors. These descriptions provide an Ayurveda framework for understanding the symptom, although they should not be treated as direct equivalents of every modern neurological diagnosis.