Why is smoking bad for the kidneys?

Decreased blood flow. Nicotine is a stimulating drug, and can cause blood vessels to constrict, or become smaller. When blood flow to the kidneys is reduced, people can sustain damage to the glomerulus, which is the filter of the kidney. Studies have shown that filtration is less effective in smokers due to decreased blood supply, and they tend to have higher levels of protein/albumin in their urine- like in diabetes.
Smoking and Kidneys. Smoking is bad for everything. In regards to the kidney, smoking increases the formation of atherosclerotic plaque which builds up in the blood vessels and cause a blockage of blood flow. When the kidneys dont receive enough blood flow, they do not function normally and start to fail.