It's been a day since i went to the hospital and they took blood. my arm is stinging and it's making it impossible to sleep. should i wait it out?

Need to examine: Is there a large bruise? Swelling? Redness? Any discharge? If it is painful enough to interfere with your sleep, you should call the hospital as it may warrant a visit to the er.

See a doctor: Your arm should not be having pain so severe that you cannot sleep after normal blood drawing. Get someone to examine this.

Arm pain: I would recommend that she be evaluated as quickly as possible, as it is unclear as to why you're having constant pain which seems to be nerve compression.