Everyone has the odd bad day at work. The train is late, the boss lands an unexpected pile of work on your desk, your computer goes on the blink and the coffee machine breaks down. But what happens when every day is bad and your frustration is escalating out of control? Anger in the workplace is an increasingly common problem, according to human resources and psychological health specialist Validium. Calls to its employee helpline have risen significantly over the past year - not just from those feeling resentment every day, but also those suffering at the hands of a permanently angry colleague.