Heavy Meth users are often involved in domestic disputes and motor vehicles accidents. They may also be present at "raves" or parties and they may participate in spur of the moment crimes, such as purse snatching's or assaults, to support their habit.

Detaining a heavy meth user alone is not recommended and law enforcement officers should call for backup.

The most dangerous stage of meth abuse for abusers, medical personnel and law enforcement officers is called "tweaking". A tweaker is a heavy Meth user who probably has not slept in 3-15 days and is irritable and paranoid.

Tweakers often behave or react violently and if a tweaker is using alcohol or another depressant, his negative feelings and associated dangers intensify. The Tweaker craves more meth, but no dosage will help re-create the euphoric high, which causes frustration, and leads to unpredictability and potential for violence.

A tweaker can appear normal: eyes can be clear, speech concise, and movements brisk. But a closer look will reveal the person's eyes are moving ten times faster then normal, the voice has a slight quiver, and movements are quick and jerky. These physical signs are more difficult to identify if the tweaker is using a depressant.