I'm not really sure what your question is. Clotting is not necessarily a danger sign, because the body should be able to clot naturally. However, sickle cells are tend to clump together more often than regular blood cells. So I guess it wouldn't really be a danger sign since it happens often...however, if the clot is in a precarious spot, like your heart, or brain, or clogging a major artery or vein, it could lead to other systemic complications like heart attacks, strokes etc. I'm not sure if I answered your question at all...