I was taking Letrozole for about nine monthswhen my hands began to be very painful. A nerve conduction study showed carpal tunnel syndrome in both hands and I prepared for surgery. I looked up the side-effects of Letrozole and carpal tunnel syndrome was one of them . My oncologist suggested a drugs holiday (now some 18 months from first taking it). It was significant- my hands improved after about two weeks- no longer woken at night with severe hand pain and able to grip things again and being able to feel objects properly was terrific. The best is that I no longer need surgery. Am now on Exemesetane and hoping the CTS does not return.