Any form of bullying creates emotional and mental stress on the person being bullied that often results in physical and psychological health issues; many already mentioned.
Cyber bullying may exaggerate the stress of physical bullying because the person being bullied may not even know who is doing the bullying. That can make them distrustful of everyone around them and fearful that the one person they confide in could be the bully.
Cyber bullying is a health issue for anyone of any age. It is especially nasty for tweens and teens who are dealing with the emotional issues of growing up, trying to establish their own emotional balance, learning to trust people outside of their small circle of family and childhood friends, and adjusting to the changes in their physical body.
More information is available through the links below, especially the Cyberbullying Research Center. Some of the statistics may differ, depending on your source, because they are based on polls done by different groups, at different times, and with different people. But all polls shows that youth are targeted frequently and cyber bullying is a big part of the problem.
Precise health issues that can result from cyber bullying include depression, anxiety, nervous breakdown, anorexia, bulimia and psychosis. All forms of bullying increase the risks of these conditions, but cyber bullying is particualrly pernicious and destructive because it can so easily be hidden behing a forum name or false online identity. Teens in particular may be reluctant to report it as they may fear consequences like their computer being taken away. Parents may not realize what's going on as teens spend so much time alone in their rooms. Anxious, withdrawn behaviors and new symptoms such as school-avoidance, sleeplessness, disorganisation and stress should be taken seriously and counselling should help alleviate the problem.
I think that part of the presentation on the health cost of cyberbullying is fairly similar to the health costs of any bullying. The targeted individual endures feeling a lack of self worth, of care for oneself. This can spin off into continue mental deterioration, being inwardly drawn, and possessing a strong distrust of both the outside world and themselves. There can be physical implications to cyberbullying, as well. Loss of appetite, trust and faith in other people, as well as potential to physically hurt onself are both quite real health consequences to cyber bullying. The presentation of health costs in both are fairly similar. I think that you can make the argument that since cyberbullying is so technologically driven, there can be a fear of simply being at home, because of the technological aspect. Whereas with the traditional bullying element, home is seen as the sanctuary, this disappears with cyberbullying, where there is constant fear in all domains that can be reached through technology.
Cyberbullying becomes a health issue because of the impact it can have on the psyche of the victim. As it affects the victim's mental state, it can also affect their health.
In the most extreme cases, cyberbullying can lead to suicide. This happens when the victim feels so ostracized by peers that life seems unbearable.
Less drastically, but still seriously, cyberbullying can stress teens in a big way. Stress can lead to all sorts of negative consequences for a person's health, like weight gain or excessive weight loss, lack of sleep, or even drug use.