Could smoking too much weed cause vomiting, convulsions and other various symptoms?

Vomiting rarely: But seizures are not part of the picture. Actually, in most people cannabis reduces nausea, and is used to combat the nausea and poor appetite of cancer treatment and other chronic diseases. However, rarely it can cause cyclical vomiting syndrome, where people get random periods of intense nausea/vomiting. Sleepiness is the usual sign of too much, though some people get increased anxiety/panic.

Weed problems?: It depends on whre the marijuana (m) was bought. If it were bought on the street, anything is possible. That's because one cannot know what the m is laced with from a street vendor. As there is no standard for street bought m, as opposed to drugs regulated by the fda, anything can happen to anyone at any time.