If the answer is yes, take a closer look as to why his or her style has changed. If your child goes from conservative and clean cut to a grunge or gothic look, keep an eye out. Or if he or she loses interest in once-loved hobbies and activities, you might want to look for the reason behind this change.

A late-night snack becomes a feast -- or perhaps a fiesta.

We all like a little late-night snack for comfort every once in a while. However, a home-concocted buffet at 2:00 a.m. can signify a whole different ballgame.

If you hear a raccoon-like teen rifling through the refrigerator in the wee hours of the morning, you’ve got a problem. That’s a dead giveaway that your child has smoked a little weed.

Before you jump to a potentially incorrect conclusion, step back and observe what’s going on.

Your teen says it's a cold, but the sniffling goes on for weeks.

The truth is that a case of the sniffles can be an indicator that your teen is on coke. That’s because cocaine aggravates sinuses and nasal passages, contributing to itching and running.

Further, your teen may get a bloody nose. If this happens repetitively, you might want to investigate the situation at hand. And losing weight also may indicate a coke habit. Both of these symptoms can be cause for worry and are worth investigating.