These are the sign of internet addiction:

• Always thinking about the internet, imagining of what is happening in the cyber world and feels disappointed and loss if not able to use it.
• Feels anxious or doubtful if not able to use the internet
• Hard to stop from using the internet, although has been using it for a long period of time.
• Experiencing psychomotor disturbance.  For instance, the fingers which often mimic the act of pressing a keyboard or using a mouse.

The effect of internet addiction is having a emotional stress and depression and the person is likely to be a loner because of his or her seldom mixing with society and friends. The internet addicts usually will have the same problem as alcoholics.

Be aware of these signs. Consult your doctor if you are feels like having internet addiction.