Recent studies highlight the blood and biochemical alterations resulting from tobacco consumption. The study examines certain toxic substances present in tobacco (nicotine and carbon monoxide) inhaled when smoking. Blood tests (complete blood count) and biochemical analyzes (creatinine, triglycerides, total cholesterol, including high-density lipoprotein (HDL) cholesterol known as "good cholesterol" and low-density lipoprotein (LDL) cholesterol known as "bad cholesterol", transaminases TGO, TGP, and calcium) were performed on smokers, compared to non-smokers, to understand the impact tobacco on the blood.