Meanings of feeling jittery in English

I was feeling jittery by then, which must be why I dropped my key.

Not usually my thing, but I'd had enough coffee this morning and I was feeling jittery.

Spencer looked away, too, feeling jittery.

Investors also were feeling jittery about how Italy, the euro zone's third-largest economy, would finance its huge public debts.

Other side effects can include rash, flatulence, loss of appetite, sour stomach, belching, heartburn, indigestion, dizziness, headache, and feeling jittery.