Hypodermic needle tips. Artwork comparing a blunt (left) and a sharp (right) hypodermic needle tip. Hypodermic needles are used to inject drugs and other substances or to extract fluids from the body. They vary in needle diameter (bore size) and in tip shape (bevel type). Some needles also have additional side holes in them, such as the ones seen in the tips here. These side holes can aid injection and extraction. An example of such needles is those used in spinal anaesthesia.