Smoking, diabetes, overwt, HTN, heart rhythm/valve disorder, phlebitis, varicose veins, migraine, epilepsy, hypertriglyceridemia, liver or gallbladder disease, Crohn's disease or ulcerative colitis, SLE, hemolytic uremic syndrome, sickle cell disease, porphyria, herpes gestationis, Sydenham's chorea, chloasma.