What are the possible sexual problems caused by hd, and what can be done about them?

Common. It is very common for people on dialysis to complain of erectile dysfunction and low libido. Many of these are psychological and can be overcome with conselling and medications. Sometimes testosterone levels can be the culprit...It's worth a test.
H.D. The problems that caused the need for H.D. Have more influence on sexual function than the H.D. Itself.