leg aching

Ive been doing hot yoga for the past 4-5 mths now. Im always
looking forward for each class actually. But until recently, i notice both my
leg (calf down to feet) aches for several days. I am wondering if i have
torn any nerve and is there any pose that i should avoid due to my unknown
illness. The pain is not muscle sore but maybe close to rheumatism aches. Is is uncomfortable. I hope someone here could assist. :-S