Some nicotine goes to other parts of the body. And if a woman is pregnant, this burst of nicotine also reaches the fetus through connecting blood vessels. In large amounts, addictive drugs like nicotine, heroin and cocaine are poisons. For example, nicotine has been used to kill insects. Nicotine makes the heart beat faster, increases the breathing rate and causes the body to use more oxygen.
Nicotine causes other changes in the circulatory system, too.
For example, blood vessels narrow. This can increase blood pressure. Nicotine also appears to increase the tendency of the blood to clot and has been linked to diseases of the blood vessels and heart. Nicotine can have different effects. Early in the day nicotine acts as a stimulant to many people.