<human>: My doctor says I have to quit smoking. What are the health risks of smoking?
<bot>: The main health risk associated with smoking is an increased risk of developing a variety of serious illnesses, including lung cancer, heart disease and stroke, as well as other respiratory diseases such as chronic bronchitis and emphysema. Smoking can also cause damage to your teeth and gums, increase your chances of developing diabetes, and decrease your fertility. In addition, secondhand smoke exposure poses a risk to others around you, especially children and pregnant women.