A hypodermic syringe is a medical tool used to inject medicine or other fluids into the body, or to draw blood or other fluids out. The word hypodermic means “under the skin”: hypo means under, and dermic refers to the dermis, which is your skin.

A hypodermic syringe has three main parts: a hollow needle that pierces the skin, a tube (called a barrel) that holds the liquid, and a plunger that pushes the liquid through the needle. When a doctor gives you a vaccine or a nurse draws blood for a test, they're using a hypodermic syringe.

Before hypodermic syringes were invented in the 1850s, giving medicine directly into the bloodstream was difficult and dangerous. This invention revolutionized medicine because it allowed doctors to deliver precise doses of medication quickly and safely. Today, hypodermic syringes help deliver everything from insulin for people with diabetes to vaccines that prevent diseases like measles and polio.

The technology seems simple now, but it represents a major breakthrough: a way to get medicine exactly where it needs to go in the body, bypassing the digestive system entirely. Many life-saving treatments, from antibiotics to emergency medications, depend on this humble but essential tool.