PSP Health Hazards
As with anything, abusing the PSP could result in health hazards. Some of them are more serious than others (and I do mean serious in both senses of the word).
Hazard 1: Hearing
Since the PSP's speakers aren't all that powerful, chances are you're using a headset or earphones of some kind. Well, remember how people who listen to music players are sometimes told that the music is too loud and they could damage their hearing? The same goes for the PSP. If you put the sound too loud, and you have earphones, you could damage your hearing. You only need a few sound bars to hear well. You do not need to put the volume on max that should only be done if you can't find your earphones.
Hazard 2: Vision
Yes, it's a small screen. However I've seen some people with their PSP right up against their face. That's not good for your eyes. Try to keep the PSP a foot away from your face.
Hazard 3: Hand Muscle Fatigue
If you're playing the PSP for a long while, you'll notice your hands will feelstrange. Having your hands lay down in the same position, while only moving your fingers, will cause muscle fatigue after too much play. If it can happen while you're using a regular controller on a regular console, why wouldn't it happen when playing on your PSP? Be sure to give yourself a break every couple of hours.
Hazard 4: Butt/Leg Muscle Fatigue & Weight Gain
This may be redundant, but if you're playing for a long time without a break, you're probably standing or sitting in place. This is bad for blood flow and bad for your muscles. Also if you're playing so much that you get these kinds of muscle fatigue, it means you're not getting exercise. If you're only an occasional player that would be fine, but if you play your PSP very often for prolonged hours, you could start to gain weight. Get to moving!
Hazard 5: Hunger & Dehydration & Kidney issues
Hey, I know how it is. You're really into this game you're playing and don't want to spend any time away from it. So you're not eating, you're not drinking, you're not going to the bathroom. You're starting to sound like some serious World of Warcraft fanatics. You know what happens to them? They pass out and can end up in the hospital. If you're doing the same thing with whatever game you're playing on your PSP, you could too!
Hazard 6: Bad Sportsmanship Syndrome
Many PSP games have multiplayer. If you can't handle losing to someone graciously, or if you're an overly-gloating winner, you could have problems. First, you may make your opponent mad. Second, he or she could decide to take revenge and that's probably not good for your health.
Hazard 7: Track of time
So you're having great fun but now for some reason you decided to stop playing (batteries died perhaps), and you've just realized you totally lost track of time and missed a meeting with someone. Whether it's an appointment, a date, a special event, your work shift, etc, you probably won't get away cleanly and the consequences could cause you depression, pain, headache, loss of money/job, and various other symptoms that could in the future be extremely hazardous to your health.
Hazard 8: Neck pain & Posture
I can't believe I almost forgot this one. If you like to lay down on the sofa or your bed as you're playing, but can't seem to get that cushion just right, you could cause yourself some serious neck pain. Also if your back gets stiff from playing, and playing, and playing, and yet you don't move it a bit, you could do damage to both your back and neck. This in turn will cause you future back pain when you wake up, and a worse posture.
Hazard 9: People around you
I don't care how frustrated you get. Do not take your anger out on those around you. This could cause THEM health issues. More importantly, never throw your PSP in anger for any reason whatsoever. Seriously, you're bound to hit someone or something you really shouldn't.
Overall:
It's easy to hurt yourself if you don't think about what your actions will do, and refuse to moderate yourself. There are even more health hazards than I've mentioned, but making a full list would take too long. So behave! You've been warned!
Now I'm off to surf the web with my back hunched over, using a horrible non-ergonomic keyboard, and staring at the screen without movement for about 6 hours. Bye!