Paresthesia occurs due to compression on a nerve. You have likely felt it when you’ve crossed your legs for too long or lay on your arm for an extended duration. It may feel like your limb has ‘fallen asleep.’ Normally, the sensation is temporary.
However in some cases, it can become a chronic problem. Cases where it goes on for prolonged periods of time include a stroke, nerve damage, multiple sclerosis, carpal tunnel syndrome, and sciatica. The course of treatment depends on the cause, but can often effectively reduce or eliminate the sensations.