For a few days now, I have had numbness in my upper left thigh. What is causing this? I have a bad back too, so difficulty in walking has been a problem.
You probably have developed a "pinched nerve" from a herniated disk in your lower back. If you have degenerative arthritis in your spine, the intervertebral discs may become herniated and press against the nerves that emanate from your spinal cord. You have to see an orthopedic or a neuro surgeon. Nowadays, there are minimally invasive procedures to remove the abnormal disc.
See an orthopedic doctor as soon as you can get in. If there's too much of a wait, go to an ER or even Urgent Care. Numbness is nothing to fool with.
Did you pull any muscles, shovel heavy snow or do anything prior to development of the numbness? What are your back issues? Any compression fractures? Kyphosis?
Your profile seems to indicate you're caring for yourself, as opposed to a relative or friends, or someone who is older, so this also is probably not the appropriate venue to respond to your questions.
Really can't and shouldn't diagnose it on a non-medical global forum. Call your clinic or nurse's line. I hope you get the medical care you need to solve your problem.
Get to an orthopedist (skip the GP's office), because you don't want permanently nerve damage.
There are a couple of interesting possibilities. Please Google, read and call your doctor in the morning.
Did you pull any muscles, shovel heavy snow or do anything prior to development of the numbness? What are your back issues? Any compression fractures? Kyphosis?
Your profile seems to indicate you're caring for yourself, as opposed to a relative or friends, or someone who is older, so this also is probably not the appropriate venue to respond to your questions.