Fig.: to be worried and nervous; to be in anxious suspense

Gloria thinks she didn't do well on her final exam and she is on pins and needles waiting for the results

Gloria pensa di non aver fatto bene l'esame finale ed è sulle spine in attesa dei risultati

Thanks God they got rid of my boss. He was a very ill-tempered man and it was pretty scary to be around him, because you never knew what in the world was going to happen next. That's why the whole world was on pins and needles around him

Grazie al cielo, hanno licenziato il mio capo! Tutti quanti in ufficio stavano sempre sulle spine, perché aveva un carattere impossibile e a volte si aveva paura a stargli vicino perché non si sapeva mai che cosa poteva succedere

Try and imagine someone sitting on pins and needles: he would move restlessly trying to find a better position to get some relief from pain