I have random sharp pain in my left top inner thigh mostly while sitting, sometimes while walking and it can almost knock me over help what is it?

It sounds very much like you have a pinched nerve in your back. All of the various nerves run along our spine & sometimes when a nerve gets ‘snagged’, you will feel it in your legs.

You might also want to get checked for deep vein thrombosis, or a blood clot in the leg somewhere.
Is the spot hot to the touch, sore in a specific area?
It could be many things from minor to serious, see your doctor to be safe.

Read about sciatica

As @Coloma mentioned, it sounds like it could potentially be a DVT. You need to get this checked out soon. If you feel it ascending (going further up your leg) call an ambulance and get into the ER right away. A DVT can break loose and shoot up your lungs causing a pulmonary embolism which can easily kill you.

I don’t want to alarm you, especially becaus there is probably a very good chance this isn’t something serious, but I did want to make you aware that you need to get it checked out soon to rule out a DVT. Again, if you feel the pain rising like a clot moving up your leg, then you need to go to the Emergency Room right away.

If it was the outer thigh that you had this pain then I would guess
that Sciatica ( which I have too) is the root cause, but since it is
the inner thigh,,get checked for uterus (ovary and falopion tube)
problems yearly.

Sometimes it seems to happen just before you menstral periods
too.
I used to experience that simular pain, and ignored it, but later in
life I had minor surgery to correct and all is OK from then on.
There are so many things such as a pulled muscle or infection?
Only by getting it looked into by a profession doctor can you finally
get relief.

I have started to experience the same kind of pain – right inner thigh, stabbing, intense and random. I find that stretching my low back, glutes and hips helps reduce the intensity, as does keeping to a minimum the arch in my low back. Also minimize sitting for long stretches. I have made an appointment with my chiropractor, who I’m sure can help.

One word. Massage.

Man did I get worked over good today, make it hurt so good. lol