Why there is pigmentation on skin with crf?

Pigmentation and CRF: The adrenal glands are positioned directly above the kidneys. As the kidneys are failing, the adrenal glands are also often affected. As the brain tries to signal for increased adrenal activity you get more adrenocorticotropic hormone (acth), this can cause increased melanocyte stimulating hormone activity causing the increasd pigmentation associated with chronic renal failure.