- Obesity
- The condition of being significantly overweight. This is becoming a particularly serious problem among children and teens. Some of the most significant health risks include diabetes, heart disease, and high blood pressure.
- Obsession
- When a person become completely focused on something to the point of neglecting other aspects of their life. It can also refer to a specific fear that a person suffering from OCD has.
- OCD
- Obsessive-compulsive disorder. This is a mental health issue characterized by uncontrollable and upsetting thought and nervous tics. Those suffering from OCD will often have anxiety issues as well.
- Olfactory Hallucination
- The perception that you are smelling something that is not there. This condition can be caused by a number of different mental illnesses and illegal substances.
- Opium
- A highly addictive drug that is the main component in many pain killers. Because of natural tolerance buildup, overdoses are common among regular users.
- Oxycontin
- An opiate based prescription pain killer that is commonly abused. This drug in particular can be dangerous and addictive.