Hemodialysis patients have a very high rate of heart attacks, strokes and amputation. These problems are caused by a blood vessel problem called atherosclerosis (hardening of the arteries), and by clotting. Clotting is also a problem in the access, which is their lifeline for hemodialysis. We have early results which show that some risk factors for clotting in the general population are common in dialysis patients. Bleeding is another significant problem within this population. In this pilot study we will measure bleeding/clotting factors in the blood of consenting patients who are just starting dialysis. We will also do special tests to show how much calcium build up and atherosclerotic build up has happened in the arteries and whether the arteries are becoming stiff. We will then follow patients for up to four years and record any health problems that might reflect bleeding, clotting or a blood vessel problem. At the end of the study, we will compare people who have had bleeding, clotting or blood vessel problem with those who have not, and learn which of the measurements predicted problems. We will go on to study potential treatments, such as anti-clotting drugs, which might prevent or delay the occurrence of such problems. This would improve the health of dialysis patients.