What causes numbness and tingling?

A limb that tingles after being compressed may recover as pressure is relieved. Recurrent or lasting symptoms can reflect peripheral neuropathy, vitamin B12 deficiency, hypothyroidism, or another problem affecting nerves, circulation, or the spine. Fast breathing during anxiety or panic disorder can produce tingling around the mouth or in the hands. The location, timing, spread, weakness, pain, balance changes, and triggers help distinguish these patterns. The sensation itself does not identify one diagnosis.

Note when symptoms begin, where they occur, whether they are one-sided, and what makes them better or worse. Protect numb skin from burns, cuts, and pressure because reduced sensation can hide an injury. Arrange a clinical review when symptoms persist, recur, spread, or affect walking, grip, or sleep. Assessment may include a neurological examination and selected blood tests. Vitamin B12 injections are used only when a clinician confirms that treatment is appropriate.

Sudden numbness or tingling on one side, facial drooping, trouble speaking, new weakness, severe dizziness, or loss of balance can indicate a stroke or transient ischaemic attack. Seek emergency help immediately, even if these symptoms improve. Urgent assessment is also needed for new numbness with loss of bladder control, severe back pain, or rapidly worsening weakness.

Does the distribution suggest nerve pressure, peripheral neuropathy, vitamin B12 deficiency, thyroid disease, or anxiety? Which examination or blood tests are relevant? How should I protect the affected area while waiting?