Brief Answer:
Possibly a neuropathy

Detailed Answer:
Hi,

Thank you for posting the query.
I have gone through your medical history in detail.

Extreme pain inside the thigh region of the leg can be caused either by a muscle strain or a nerve inflammation (neuropathy).

Have you suffered from a recent injury?
Have you lifted anything heavy in last few days?

Sometimes a nerve compression in the lumbar spine may cause radiating pain to the thigh region.
Very rarely,affections of the hip joint can cause such kind of pain.

I would suggest you to get an Xray and MRI of the Left hip and thigh region to confirm the diagnosis.MRI of the lumbar spine may be necessary.

You should consult a nearby orthopedic surgeon if the pain is extreme.

Till then,analgesic medicines like ibuprofen or tramadol along with pregabalin,methylcobalamin and folic acid would be helpful.

Adequate rest is essential for speedy recovery.

I hope the answer was useful to you.

Best wishes.

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