Signs of overdose or intoxication from cannabis use can include: impaired coordination and motor control, confusion, anxiety, paranoia, increased heart rate, dry mouth and eyes, red eyes, sleepiness or fatigue. In more severe cases it may lead to nausea and vomiting. People who have taken too much cannabis may experience hallucinations or delusions as well as an altered sense of time and space. It is important to seek medical attention if any of these symptoms occur following the use of cannabis.