Any substance that causes a change in a person's physical or psychological state.

A dependence on a substance, such as alcohol or drugs.

A toxic, addictive chemical that is found in tobacco and that is one of the major contributions to the harmful effects of smoking.

A disorder in which a person repeatedly drinks alcoholic beverages in an amount that interferes with the person's health and activities.

A drug that is derived from opium and that relieves pain and induces sleep, examples include heroine, morphine, and codeine.

The science of health and ways to preserve health.

aerobic exercise

Physical exercise intended to increasse the activity of the heart and lungs to promote the body's use of oxygen.

A physical or mental response to pressure.