What are some common physical signs associated with stimulant use?

Hallucinations and dry mouth are physical signs that can be associated with stimulant use. Stimulants such as amphetamines can lead to an increased state of alertness and euphoria, but they can also cause sensory distortions, such as hallucinations, particularly in cases of high doses or prolonged use. Additionally, dry mouth (xerostomia) is a common side effect of stimulant drugs due to their impact on the body's autonomic functions and saliva production. These symptoms are indicative of the body's reaction to the chemical changes induced by stimulant substances, helping to identify potential misuse or dependency in an individual.

The other options do not accurately represent the physical signs typically associated with stimulant drugs. Pupil constriction, increased appetite, drowsiness, weight gain, and paranoia are more commonly associated with depressants or substances where relaxation or sedation is a primary effect, rather than the heightened energy and alertness produced by stimulants.