Cannabis has a chemical constituent called tetrahydrocannabinol (THC), responsible for its characteristic short term effects:
- Muscular relaxation that can cause loss of coordination and balance as well as increasing the reaction time to stimuli
- Decreased muscle strength and slight drowsiness
- Dilation of blood vessels that manifests in the red eyes
- Increased pulse and heart rate
- Dry mouth and less saliva
- Coughing and irritation
- Occasionally, it may cause negative reactions of panic and terror.
It can also cause lack of motivation, characterized by loss of interest in social relationships and activities, and a generally passive attitude toward others.