Why do people get so irritable after stubbing their toe?

Is there a reason why small pains such as a stubbed toe or a smashed finger tend to incite anger? I stubbed my toe really hard the other day, and for the next several minutes just about everything really pissed me off. I found everything that anyone said to me very irritating, and I couldn’t focus on anything. Does this happen to you? Is there a reason for this?