Acupuncture needles are designed so thin that when they go in, they don’t cause any sensation. In fact the thickness of acupuncture needles are couple of times less than a single hair, and significantly less than a syringe needle. Also the design of acupuncture needle is different from other forms of needles: For example, syringes have a cutting edge, whereas acupuncture needles are like a wire with a handle to slide in and out of the skin with no resistance and no damage.