Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
What Causes Numbness On Thigh After Injecting Vitamin B12?
Question: I recently gave myself an I jettison of B12 in my thigh. Almost immediately afterwards, I started feeling numbness on the outside of my thigh. Is this normal?
Brief Answer:
Numbness is not normal
Detailed Answer:
Hello,
I suppose you've used the front middle third of your thigh. The nerves pathway are mostly on the back of the thigh but some nerves pass though the inner part of the thigh, so if you've injected it somewhere near, then perhaps the nerve has been irritated somehow. If you had lanced the nerve itself you'd probably feel an immediate electric shock like pain, so it's possible that you've injected it somewhere near the nerve and the liquid applied pressure on the nerve or caused some sort of irritation.
Another potential explanation is having hit a blood vessel and the formation of a hematoma, which may feel like pressure (or numb) and perhaps a little painful (depending on its size and location). The thigh may hold a lot of blood without being evident, so a hematoma is a possibility.
In any case you can't do anything about it right now, unless symptoms get very severe. If they do, you should contact your doctor. Radiological imaging can prove whether a hematoma occured. Treatment of hematomas is usually conservative but sometimes (when severe pressure is exerted) a more aggressive approach can be adopted.
I hope I've helped!
If you'd like to ask for clarifications, please use your follow-up questions to do so.
Kind Regards!
Numbness is not normal
Detailed Answer:
Hello,
I suppose you've used the front middle third of your thigh. The nerves pathway are mostly on the back of the thigh but some nerves pass though the inner part of the thigh, so if you've injected it somewhere near, then perhaps the nerve has been irritated somehow. If you had lanced the nerve itself you'd probably feel an immediate electric shock like pain, so it's possible that you've injected it somewhere near the nerve and the liquid applied pressure on the nerve or caused some sort of irritation.
Another potential explanation is having hit a blood vessel and the formation of a hematoma, which may feel like pressure (or numb) and perhaps a little painful (depending on its size and location). The thigh may hold a lot of blood without being evident, so a hematoma is a possibility.
In any case you can't do anything about it right now, unless symptoms get very severe. If they do, you should contact your doctor. Radiological imaging can prove whether a hematoma occured. Treatment of hematomas is usually conservative but sometimes (when severe pressure is exerted) a more aggressive approach can be adopted.
I hope I've helped!
If you'd like to ask for clarifications, please use your follow-up questions to do so.
Kind Regards!
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
