I DARE say many of us suffer from this I am at my wits end with it. I am on Windows 7. Google Chrome I did download grammarly  which I find uuseful but am wondering if it is the cause of my problem. I also downloaded touchfreeze, has any one some advice on this matter, it is driving me bonkers.                                                                                                                                                                                                                                                                                                                                                                                                            desktop or laptop?
mouse or touchpad?
if mouse; USB or wireless?

and if you remove those two recent additions, does the problem go away?
what about a different browser?
Thank's Mark, Desktop, I do not want to change my browser, the problem started ages ago, that was why I tried touch freeze and Grammarly,  I also downloaded a programme that was supposed to FIX it but turned out to be a FULL scan lot of rubbish which I soon deleted, usually I can only type a dozen words before it runs away, funny, but today it is behaving, yet I have done nothing.  I will get back to you in a couple of days to let you know how it is going Cheers/ USB or wireless mouse?
if wireless, change the batteries.
it would still be WORTH REMOVING those recent software additions AND changing browser just to test the theory and cross them off the list of potential causes.
Thanks Mark changed batts  all o/k now.phew - easy fix then.
they're the best sort.