Over the long term, computer addiction can cause physical damage. Using a mouse and keyboard for many hours every day can lead to repetitive stress injuries. Back problems are common among people who spent a lot of time sitting at computer desks. Late-night computer sessions cut into much-needed sleep time. Long-term sleep deprivation causes drowsiness, difficulty concentrating, and depression of the immune system . Someone who spends hours at a computer is obviously not getting any meaningful exercise, so computer addiction can indirectly lead to poor overall physical condition and even obesity.