The most common cause of pins and needles is a moderately pinched nerve. Pins and needles is referred to as paraesthesia in the medical community. Did you know that feeling pins and needles can actually be a worse sign than having pain in your arm or leg. This is because the nerve is squashed so much that you can't even feel pain anymore. Even worse than pins and needles is numbness or anaesthesia , which is a total lack of sensation. You will experience anaesthesia when there is severe nerve compression. Anaesthesia or numbness that persists for more than a few hours can be sign of permanent nerve compression.