irrittability=an irritation...somebody's anxiety in their voice, somebody's voice, somebody's breathing, somebody's comment, not being comfortable, the way somebody eats, the questions people ask, besides physical things such as fabric irritating you at times when normally it wouldn't irritate you...these can drive you to anger or maybe are from underlying anger and anxiety. During these times, a pet may have an accident and that won't phase you whereas if you spill just a drop of coffee you might go ballistic
more later
Bobby{"The first three moods here are particularly characteristic of agitated depression.

Irritability
Almost everyone becomes irritable now and then. The reasons are almost without number. A headache, a bad night's sleep, an upcoming dentist appointment, an unexpected bill - any stressor can bring it on. But when there is no apparent reason why the least little thing becomes an annoyance, and the mood persists for days or weeks, look for depression as the cause."