When you smoke, toxic chemicals from tobacco enter your bloodstream.
Some of these chemicals send signals to your heart to beat harder and faster.
Smoking also causes blood vessels to constrict (become
more narrow), forcing blood to travel through a smaller space. Both of these
effects cause temporary high blood pressure. Long-term smokers may eventually
develop high blood pressure all of the time because of their smoking. Smoking
also increases bad cholesterol (low-density lipoprotein) and lowers good cholesterol
(high-density lipoprotein) in your body, and increases the likelihood of plaques (fatty buildups) collecting on the inside of blood
vessels, a condition called atherosclerosis (hardening
of the arteries). Smoking also increases the risk of thrombosis (blood clots blocking a blood vessel). Over time, these effects increase
the risk of having a myocardial infarction (heart