What if a vitamin B12 injection does not relieve numbness and tingling?

Nerve symptoms may take time to settle, particularly when they have been present for a while. Continued symptoms can also mean that the B12 level was not the only factor, the underlying problem needs different treatment, or the treatment plan needs adjustment. Diabetes, pressure on a nerve, some medicines, alcohol use, thyroid disorders, and other nutritional problems can affect sensation. The pattern matters: symptoms in both feet differ from symptoms on one side or in a single hand.

Do not take extra injections or supplements without medical advice. Note when the symptoms began, where they occur, whether they are spreading, and whether weakness, balance changes, or pain accompanies them. Take your medicine and supplement list to the appointment. A clinician may review blood tests, examine sensation and reflexes, and decide whether further testing or a different treatment is needed. Protect areas with reduced feeling from hot water, tight footwear, and unnoticed injuries.

Seek urgent medical help if numbness starts suddenly, affects one side, or comes with facial drooping, trouble speaking, severe headache, new weakness, loss of balance, or confusion. Get prompt care for rapidly worsening symptoms, loss of bladder or bowel control, or numbness around the inner thighs. These features need assessment even if you recently had a vitamin B12 injection.

Ask whether the timing and dose of treatment fit your results, whether another cause should be checked, and which changes would mean you should seek urgent help. Ask how to monitor recovery and how to prevent foot or hand injuries while sensation is reduced.