• A kidney transplant is a surgery to place a healthy kidney from a living or deceased donor into a person whose kidneys no longer function properly. During kidney transplant surgery, the donor kidney is placed in your lower abdomen. Blood vessels of the new kidney are attached to blood vessels in the lower part of your abdomen, just above one of your legs. The new kidney’s urine tube (ureter) is connected to your bladder. Unless they are causing complications, your own kidneys are left in place.
• The kidneys are two bean-shaped organs located on each side of the spine just below the rib cage. Each is about the size of a fist. Their main function is to filter and remove waste, minerals and fluid from the blood by producing urine.
• When kidneys lose this filtering ability, harmful levels of fluid and waste accumulate in the body, which can raise blood pressure and result in kidney failure (end-stage renal disease). End-stage renal disease occurs when the kidneys have lost about 90% of their ability to function normally. End-stage renal disease occurs when the kidneys have lost about 90% of their ability to function normally.
• Common causes of end-stage kidney disease include:
• Diabetes
• Chronic, uncontrolled high blood pressure
• Chronic glomerulonephritis — an inflammation and eventual scarring of the tiny filters within the kidneys
• Polycystic kidney disease

Reference:

https://www.mayoclinic.org/tests-procedures/kidney-transplant/about/pac-20384777