As I'm writing this, I'm paying so much attention to breathing normally that it's distracting. That means I usually hold my breath when I'm writing, and apparently so do 80% of other people: http://www.businessinsider.com/email-apnea-how-email-change-breathing-2012-12#!Hmz37
Next time you're reading an email or facebook post, pay attention - do you hold your breath? It really surprised me that I never noticed this before, but I definitely do it, so now I have to put some effort into correcting it.
How much time do you spend on the computer? If it's all day, every day at work, how much low-level oxygen deprivation is that causing?
Pay attention to breathing while you're on the computer for the next few days. If you're holding your breath or changing your normal breathing patterns in some significant way, try to correct it whenever you notice. Like any habit, it will take a while before you breathe normally without thinking about it. Take breaks between emails and take a couple slow, conscious breaths before you move on. It could help correct the oxygen loss from email apnea, and it just might make you feel more relaxed overall.