Blood

Changes in the blood that are caused by smoking are increased stickiness and clumping of platelets and shorter platelet survival. Thus, you experience a slower blood clotting time. This means that when you have a cut that bleeds, it takes longer to stop bleeding. Also, smoking increases the amount of fat, sugar, and hormones in your blood. This makes your blood thicker, and your heart must work harder to pump this thick blood through your body.