Soon after waking, I began to shave, and my left arm (lower arm) felt suddenly hot and fuzzy and stiff. it hasn t gone away. Examining my arm, i found a slightly elevated knob, slightly pink, about four inches below the hinge in my arm. When i rub it, it is tender and i can feel a warming sensation up and down the arm--mostly down. I think it is a blood clot. A few months ago, I think i had a severe blood clot in my left ankle--i couldn t walk on it, but the more i did the pain seemed to alleviate--in the same day, then it went away in a day or two. At the time i was sedentary, at my desk. But I walk up and down 6 flights of stairs everyday, twice, thrice...I am 36, relatively fit, normal weight, eat fairly good, don t smoke , don t exercise as much as I used to, never much, drink coffee, experience sinus headaches from time to time. if this is a blood clot should i worry too much. i want to go ride my bike now, thinking exercise will be good for me, just did some brief calisthenics. i don t want this to be a blood clot.