What Could Cause Bleeding Of The Capillaries In Lower Legs?

Hi: I do a lot of walking. Whenever I walk over 12 miles I end up with my lower legs being bright red. I was told that it is the bleeding of the capillaries, but that it is not cause for alwarm as there is no damage being done. I have resisted wearing the compresion socks in the hot weather. I would like to find out why this is happening and what can be done (if anything) to prevent it. Yesterday I walked 10 miles, stopped for 15 minutes, walked a mile, stopped for 15 minutes, walked 1.5 miles, stopped for 45 minutes (lunch), and then walked another 1.5 miles. This was all done on flat ground. Where the redness was usually contained just above the ankles it is now solid through the calf area with spots as high as just below the knee. Any suggestions would be appreciated. If need be what type of specialist should I see? Thank you - George