Yeah man, it's tricky. I have been a daily smoker for about 9 years, and of course, this has happened to me plenty of times. What you have to realize is that you are smoking a substance that alters brain function, blood circulation, heart rhythm, etc. The intensity of these effects vary from person to person. That is why some people REALLY love to smoke marijuana, and some REALLY can't smoke it. As others have said, your environment, current mental/emotional state, source of substance, etc. can all play a role in how your body reacts to the stimulation. Nowadays, you really have to trust that what you are getting is quality. Which is an excellent argument for decriminalization. A seemingly safe plant like marijuana can be covered in dangerous chemicals during the growing/harvesting/transporting, and thus passed into the lungs and blood stream of the smoker. Now, as for prevention?? It's tough. I have come to the understanding that I control my body. Nobody else is running my brain. So when I start to feel a panic attack, or extreme paranoia... I slow down and "dive into myself." I let my body know who is running sh*t here. Being in tune with your body is extremely important, especially when using substances. Meditation, and understanding the mind-body connection is essential to controlling your bodily responses. Maybe that paranoia and anxiety exist in your body all the time, and smoking just brings it to the forefront?? Forcing you to deal with the awful feelings, uncontrollable fear and confusion. Think of it as a blessing. It is a terrible way to feel, but when you break through and figure out how to control it... it is an incredible feeling. Sorry if I rambled... I'm high and really relate to your story. This forum is awesome for quality information... so you are already on your way to understanding. Good luck! :thumbsup: