Addiction. Addiction alters one's ability to think clearly, make good choices and use sound judgement. It affects lives negatively usually in the form of time spent obsessing over obtaining the drug, and using the drug. As a result, relationships start suffering due to lack of nurturing and the person may even start missing work. The addict can no longer feel normal without the substance they are abusing.
Many. If you are taking vicodin when the pain is gone or minimal... If you feel you "need it" or get shaky or anxious without it... You're addicted. Don't panic. A slow taper (increasing the time between doses and decreasing the doses) can get even a moderate user off in a few weeks. Be upfront with your doctor, agree to a schedule. If this doesn't work, you may need additional support.