A hypodermic needle is a hollow needle used to inject medicine under the skin or draw blood from the body. The word comes from Greek roots meaning “under the skin.” When you get a vaccine or have blood drawn at the doctor's office, a nurse uses a hypodermic needle attached to a syringe.

The needle is extremely thin and sharp, designed to pierce the skin with minimal pain. Inside the hollow needle, liquid medicine can flow into your body, or blood can flow out into a collection tube. Before hypodermic needles were invented in the 1850s, doctors had no good way to get medicine directly into someone's bloodstream.

Hypodermic needles revolutionized medicine. They made it possible to give people life-saving medicines quickly, vaccinate millions against diseases, and help doctors understand what's happening inside the body through blood tests. People with diabetes use hypodermic needles daily to inject insulin, a medicine that keeps them healthy.

Many people feel nervous about needles, which is completely normal. But the brief pinch of a hypodermic needle has prevented countless diseases and saved millions of lives. Modern needles are so precisely made that the puncture they create heals within minutes, leaving barely a mark.