This is Dr Basu, experienced Internal Medicine Specialist.
I am here to address your concerns and provide great service.
Upper left thigh pain can be due to the nerve compression at the lumbar spine commonly.
Sleeping on one position for long time can cause nerve compression.
Lower spine arthritis is the likely cause.
Muscle spasms are another possibility.
You can try over the counter Naproxen and magensium supplements for the symptom relief.
Lower back exercises also may help.
Please also discuss with your doctor.
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