Immune system diseases (If you have kidney disease due to lupus, your doctor will call it lupus nephritis.) Long-lasting viral illnesses, such as HIV/AIDS, hepatitis B, and hepatitis C. Pyelonephritis, a urinary tract infections within the kidneys, which can result in scarring as the infection heals.
By Dr Ananya Mandal, MD. Nicotine has strong mood altering effects and can act on the brain as both a stimulant and a relaxant. Once within the bloodstream, nicotine may circulate around the body until it reaches the brain.
It's because nicotine may help people feel calmer, causing temporary feelings of relaxation as well as reducing stress, anxiety and even pain [source: World Health Organization ]. In spite of that relaxation, though, nicotine actually increases physical stress; its effects are considered a bit of a paradox. It perks up the central nervous system, but depending on the dosage some smokers find nicotine also acts as a sedative.