How can tobacco affect the excretory system?

decreases oxygen flow to body

causes colorectal cancer

causes a stroke

causes ulcers

Tobacco decreases oxygen flow to body and can cause many harmful diseases.

Explanation:

Tobacco causes oxygen deficiency in the body which directly affects the flow of oxygen in blood. For this reason, a smoker can have severe respiratory issues.  Oxidation stress is a type of stress that leads to increased exposure of oxidants and decreased intake of antioxidants. Therefore, tobacco at first affects the respiratory system and slowly starts damaging the other organs of the body including the excretory system. It can even cause lung carcinoma that can have brain, skin or rectal metastasis.