What Causes Dizziness And Soreness In The Thigh?

I am currently in the hospital. Yesterday I had a sudden onset of dizziness, loss of body strength and feeling being drunk. This only lasts 5 to 15 mins. All tests are negative. My only complaint is a sore thigh that is constantly swollen and difficult to stand or walk on. I have had 5 episodes in the past 2 days but can feel similar by exercising the leg while laying in bed.