question: my mother is suffering from cancer from last 10 yrs she has taken 28 chemos along with 26 radiaton,now she is suffering from back pain in her L4 -L5 there is harniation grwoeth her left lef is paining due to that  and now from last two days i hv seen a black reddish patch on her right leg,Please will you help in what is that black patch is this any kind of blood clot?