Table of Contents

Hypodermic Needles Types

hypodermic needle

The word hypodermic is derived from two Greek words, hypo and dermic. Hypo means under, and dermic means skin. A hypodermic needle features a hollow point securely attached to a syringe for injecting or withdrawing fluids from the body to an IV set for intravenous infusion. It is also utilized in procedures like venipuncture to extract blood from veins.

What is a Hypodermic Needle?

Hypodermic needles are medical tools that go under the skin or enter the skin. They are commonly known as Sharps. Hypodermic needles are quite skinny. Moreover, their shapes are hollow tube-like and have sharp tips.

Background of Hypodermic Needle

It is named a hypodermic needle because there was a surgeon who discovered the term hypodermic in 1858. He invented this unique word to define and elaborate on the term injection. He was Charles Hunter, a great surgeon from London.

Structure/ design of Hypodermic Needle

Cannula structure
Cannula structure

The hypodermal needles have three parts.

Hub: this part is made of polypropylene, and it fits on top of the different sizes of syringes.

Cannula: the cannula is a hollow tube-like long needle that is made of stainless steel.

Cap: it is usually made of PP and used to protect the cannula from contamination.

Hypodermic needle
Hypodermic needle

Different components, such as a plunger, a cap, a needle, and a barrel, are assembled and used to develop a syringe. The assembly machine is specifically used during the assembly process.

The Gauge of The Needle

The needle’s gauge refers to the inner measurement or the hollow part of the needle.  The needle’s diameter is measured with a Birmingham gauge (Sub iron wire gauge). In hypodermic needles, the gauge and length of the needles are inversely proportionate to each other. When the gauge increases, the length of the needle decreases. The 16 gauge needle will have a 40mm length, and the 30 gauge needle will have an 8mm length.  

needle size
Needle size

The 25 gauge needles to 30 gauge needles are commonly used in aesthetics clinics for dermatological procedures such as anti-wrinkle injections and Botox.

Types of Hypodermic Needles and Their Uses

Generally, there are four main types of hypodermic needles, depending upon their usage.

  1. Intramuscular injection
  2. Intradermal injection
  3. Subcutaneous injection
  4. Intravenous injection

Differences among the Types of Hypodermic Needles and Their Functions:

The Type of injectionFunctionGaugeNeedle length
Intramuscular injectionIt delivers medicine directly into the muscles.needles vary between 20g – and 29g13 mm to 16 mm
Intradermal injectionIt is used to deliver substance just beneath the dermis. It is preferably used to test skin allergies.needles vary between 25g and 30g8mm to 13mm
Subcutaneous injection It is used to inject medicine in the subcutaneous layer between skin and muscles, for example, insulin in diabetes patients.needles vary between25g and 30g1/2” – 5/8” or 4mm to 8mm.
Intravenous injection It is used to inject directly into the veinsneedles vary between 20g and 25g1/2” or longer

Uses of Different Types of Hypodermic Needles

As mentioned above, different types of hypodermic needles are used for other functions. Here are the details of the uses of the four types of hypodermic needles.

Intramuscular injection

This type of hypodermic needle delivers medicines directly into the muscles. While injecting any substance, the needle is placed at an angle of 90 degrees with the skin. This type of needle is most commonly long in size. Hence, 20 gauge needles to 23 gauge needles will work perfectly for intramuscular injection. However, some practitioners also like to use 25 gauge needles to 29 gauge needles. The length of an intramuscular injection needle is usually between 13mm to 16mm.

Intramuscular Injection 23G
Intramuscular Injection of 23 Gauge Needle

Intradermal injection

Intradermal injections are used where the needle needs to be injected just under the dermis, below the upper layer, or epidermis of the skin. The most common uses of these injections are tuberculin skin testing, allergy testing, and injecting local anesthesia. A 25 gauge needle to 30 gauge needle is preferably used while administering an intradermal injection. The needle’s width is usually small, 0.5mm to 0.3mm, and the length varies between 8mm to 13mm. An angle of 10 degrees is made with the skin when the intradermal needle is injected.

Intradermal Injection 27G
Intradermal Injection of 27 Gauge Needle

Subcutaneous injection 

The term subcutaneous means under the skin. This type of hypodermic needle is used to deliver medicine into a layer of tissues called the subcutaneous layer present between skin and muscles. These injections are well known for injecting insulin in patients suffering from diabetes. Medicine delivered with subcutaneous injections is absorbed more slowly. Sometimes, it may take 24 hours for the absorption. 25 gauge needles to 30 gauge needles are preferred for subcutaneous injection and the usual needle length is 4mm to 8mm.

Subcutaneous Injection 25G
Subcutaneous Injection of 25 Gauge Needle

Intravenous injection 

These injections are used to inject medicine directly into the veins, and the medicine enters the bloodstream. Hence, absorption is quick. These injections are one of the most common health practices worldwide. They are used in emergency cases such as heart attacks, poisoning, or stroke. 20 gauge needles to 25 gauge needles are preferred for intravenous injection.

Intravenous Catheter 21G
Intravenous Catheter of 21 Gauge Needle

General Uses of Hypodermic Needles:

  • These needles are used for the speedy delivery of substances.
  • Hypodermic needles are commonly used with Luer lock or Luer slip syringes to inject substances inside the body, such as liquid medicine or drugs or saline solution, or to extract fluids from the body, such as blood.
  • The hypodermic needle plays a significant role in research requiring hygienic conditions. Using hypodermic needles for the prevention of contamination during the inoculation process (a process in which artificial immunity is induced in the subject) has been proven effective.
  • These needles reduce the chances of contamination due to two reasons. One reason is that the hypodermic needle’s surface is smooth, so the airborne pathogens cannot trap on its surface. The second reason is their surface is very sharp. So, the hole diameter that resulted while puncturing the membrane is very tiny, and the microbes cannot contaminate the subject. Nevertheless, it remains imperative to exercise caution and abstain from the indiscriminate reuse of needles. Employing syringes and needles more than once poses potential hazards, such as the proliferation of infections, transmission risks, the possibility of inflicting injuries, and the likelihood of causing pain.

Company Introduction

Liaoning KANGYI Medical Equipment Co., Ltd was founded in 1994 and is one of the leading manufacturers of IV sets, syringes, and medical parts in China. Quality is our highest priority, and our quality assurance system is certified and meets the standards of the Chinese National Medical Products Administration, ISO 13485, and the European Union’s CE mark.

We produce over 600 million pieces per year. Our products are sold across China and exported worldwide, to destinations including Europe, South America, Russia, Africa, and the Middle East.

Our company employs over 300 staff, including 50 people working in engineering and technical management. Our premises occupy an area of 20,000 square meters, with a construction area of 15,000 square meters. This space includes a 100,000-class purification workshop that occupies 8,000 square meters.

If you want to know more about us and talk face to face, we welcome you to visit our booth in CMEF Shanghai and Hospitalar in Brazil.

Related Articles

Tag: insulin needle Tag: parts of needle Tag: reuse needles and syringes Tag: parts of syringe and needle Tag: hypodermic injection Tag: parts of a needle Tag: syringe needle Tag: needle parts Tag: syringe needle sizes Tag: 21G Tag: IV catheter Tag: hypodermic needle Tag: hypodermic needles

Handle and Care of Syringes, Needles& IV Tubing

IV Set Size

IV Set Price

What is an IV Roller Clamp?

What are the Differences Between Infusion Set and Blood Transfusion Set

The Difference Between Scalp Vein Set And Intravenous (IV) Catheter

What is Luer Lock IV Set?

What are the Differences between Intravenous Infusion and IV Bolus?

Famous Types of IV Sets In Turkmenistan

What is a 2-Part Syringe?




3 thoughts on “Hypodermic Needles Types”

  1. Carey Tyler Schug

    looking for a non-needle. no sharp point, for reaching down into the pocket around a tooth to flush out trapped food. blunt point, hole on the side.

Leave a Comment

Your email address will not be published. Required fields are marked *

Let's Have A Chat

Get our catalogue or lastest news and updated products!