The effects of smoking are felt within a few minutes and last two to four hours. Performance of complex tasks may however be impaired for as long as 24 hours. When cannabis is eaten, the effects appear more gradually, last longer and are more difficult for the user to control than when it is smoked. The high is the most common effect of cannabis and the reason most people use the drug. Also, sensory perception seems enhanced.
Colors appear brighter and sound more distinct.
The user may misjudge the passage of time so that minutes seem like hours. Appetite often increases, especially for sweets. The physical effects of cannabis use include rapid heartbeat, red eyes, and dry mouth and throat. The increased heart rate and effects on blood pressure can be dangerous in older persons and individuals with heart disease or high blood pressure. Cannabis use impairs perception, judgment, balance, motor coordination and reaction times.