Thinning hair can be caused by a number of things. Your thyroid could be underactive, if you had surgery and had anthestetic, that can cause hair to thin. Hormones, medication, and just plain age and heredity can all play a part in thinning hair. I have never heard of too much time in front of the computer causing thinning hair, so I am sure that isn't the problem. If your hair was coming out in handfuls, I would suggest to have blood work done. But you are to lose 100 hairs a day, but the ones you lose have already replenished themselves. Hope this helps!