[Cat S]

I was just walking around my house when it happened. I didn't do any strenuous excersizes that day. I felt this sharp pulsating pain in my left thigh muscle to the point where I doubled over in pain. I then sat on the floor and it went away. I got up and was fine for about 5-10 minutes and then it happened again. It kept happening over and over again during the night each time getting more painful. I took a tylenol and went to sleep. Today my leg feels stiff and sore, but the the sharp pain in my thigh happens only once in a while and sometimes when I turn a certain way. At first, I thought I just pulled a muscle like I have done many times before (I'm a dancer), but it was never that painful. Can someone please give me an idea of what it is or what I should do?I'm 18 if that helpsSomeone told me that is might be sciatica... but isnt that more common in older people?