If a patient is undergoing an injection in a hospital setting or expected to perform this routine procedure at home, they’ll use a syringe with an attached needle.

In considering this arrangement, syringe size is based upon use and amount of solution that will be administered. The needle, meanwhile, is based on the solution type, injection depth and location, and the syringe tip. 

About Hospital Syringes

Typically disposable to prevent the spread of blood-borne illnesses, syringes consist of three basic parts: a barrel, which holds the medication or solution; a plunger that assists with the injection; and a tip, where the needle is attached. Volume will be listed in centimeters or milliliters, based on how much the syringe is built to hold. 

Syringe type is defined by the tip present. These include:

• Luer lock, ideal for quickly inserting and detaching the needle and requiring a twist motion to secure it in place. 
• Slip tip, similar to a luer lock syringe but without the twisting and locking function.
• Eccentric tips, also called a luer eccentric tip, featuring a tip in line with the barrel’s side and ideal for making injections parallel to the skin. 
• Catheter tip, designed for doing injections with tubing or for wound irrigation. 
• Permanently attached needles, a disposable, one-piece solution for administering lower doses of medications. 

About Hospital Needles

For these applications, needles attach directly to the syringe tip. Available in multiple sizes, their hollow composition typically includes a beveled tip to streamline the injection process, as well as a cap to reduce potential stick injuries. 

Hospital needles include three basic types:

• Hypodermic needles are used for administering medications into the subcutaneous tissue. 
• Intravenous needles are for injecting a liquid solution into a vein. 
• Sample needles are used for obtaining a portion of blood, tissue or fluid for analysis. 

You’ll select the appropriate needle based on:

• Gauge, or the diameter of the needle. Thicker needles are needed for durability and administering more viscous fluids, while thinner gauges reduce pain and are for less-viscous solutions.
• Length. This applies to how deep the needle will penetrate, including the skin (intradermal injection), subcutaneous tissue or the muscle. 
• Application. Along with all factors mentioned, you’ll want to select a needle based on the syringe size and tip type, the location of the injection, and the fluid being injected.