What Causes Severe Leg Pain Along With Body Tremors And Dizziness?

Hi my girlfriend is currently suffering with severe leg pains, which leads to her legs and eventually whole body violently shaking. Sometimes it puts her into a fit and then she passes out on the odd occasion, when things get to that stage she gets dizzy, can t concentrate and sweaty. She has been to hospital with this problem but as of yet they have failed to find anything, I just wondered if I can do anything to help ease the pain at home when it occurs. And if you could possibly suggest what it may be?.