Medical Needle Types, Sizes, Color-Coding and Uses

Hypodermic Needle and Sizes


A needle is a hollow shaft whose tip is sharp commonly used with a syringe to inject substances into the body or extract samples from the body.

For example; taking a blood sample from a vein in venipuncture.


Check out here parts of needle and syringe.


Needles are used to injecting medication in-


1. Fatty tissue; subcutaneous injection  

2. Into a muscle; intramuscular injection

3. Into dermis; intradermal injection or 

4. Directly into the vein; intravenous injection


Get here details on intravenous injection for intravenous drug administration.


Types of Medical Needle


Needles are available in a range of gauges and lengths.


1. Regular bevel

2. Short bevel

3. Intradermal bevel

4. 5-bevel

5. Blunt tips

6. Safety tips

Types of Medical Needle

1. Regular Bevel


Regular bevel is the most common tip type of needle, used for subcutaneous and intramuscular injections.

Regular bevel is the sharpest point available for hypodermic needles.


2. Short Bevel tip


Short bevel tips are used for specialty applications such as arterial blood gas sampling or nerve blocks. 

Short Bevel tip type of needle allows penetration of the skin and delivery of local anesthetic to the desired anatomical location.


3. Intradermal Bevel


Intradermal bevel offers low-angle insertions just below the epidermis means dermis skin layer.

Intradermal bevel needle tip is a used method for skin testing for allergies.


4. 5-Bevel 


5-Bevel type of needle found to be less painful for patients. 

A 5-bevel needle is most preferable, more comfortable, easier to insert, and less painful.


5. Blunt tips or Dispensing Needles


Blunt tips needle is specially designed to help to reduce the risk of needle stick injury during medication preparation like filling syringe from mediation vial or filling a syringe from an ampule.


Note - Blunt fill needles are never to be used for skin injection.


Blunt-tip syringes are used to inject medication into an IV line and also use to flush the IV line with saline solution.


6. Safety tips 


Safety tips type needles protect the user from accidental needle stick injuries. They are available in safety glide, shielding.


Know here different types of syringe tips.


Medical Use of Needle


Some of the medical needles used as-


1. Hypodermic Needles

2. Huber Needles

3. Spinal Needles

4. Pen/Insulin Needle

5. Dialysis and Fistula Needles


1. Hypodermic Needles


A hypodermic needle is used to inject liquid substances into the body and also used to take for sampling from the body. 


2. Huber Needles


Suitable for all cases when a long-term intake of chemotherapy drugs, antibiotics, painkillers, as well blood transfusion, and full parenteral nutrition is given to the patient.


3. Spinal Needles


Spinal needles allow for lumbar puncture for spinal anesthesia, diagnosis, or treatment.

It is used for a lumbar puncture to take cerebrospinal fluid (CSF) sample.


4. Pen/Insulin Needle


Insulin injections are to inject insulin under the skin subcutaneously. Insulin injection can be injected-


1. In the arms

2. In the Abdomen

3. In the thighs

4. In the buttocks


5. Dialysis and Fistula Needles


This Needle is designed specifically for hemodialysis cannulation.



Length of Needle


Length range of needle; ½ inch-3½ inches

For example, 

22G 1/2 needle - gauge of 22 and a length of half (1/2) an inch.


length of medical needle

Size of Needle- Needle Gauge


Diameter range of needle; 6 Gauge - 34 Gauge.


The needle gauge size indicates, the diameter of the lumen (opening) of a needle.

Note - The higher of needle gauge, the smaller the diameter of the needle.

As the needle gauge number increases, the size (diameter) of the needle decreases. 

For example, 

27 G needle has a narrower lumen than a 17 G needle.


Insertion of higher gauge number needle, less pain experienced by the patient.



gauge of needle

The lower needle Gauge number is stronger and less chance of bending or breaking.


Check out here what is iv cannula and types of iv cannula, and their uses.


Choose Needle Gauge Sizes for Administration


1. Subcutaneous injection

For subcutaneous injections, the needle required is small and short, with a gauge of 19G to 27G.


2. Intramuscular injection

For intramuscular injection, the needle must be thicker and longer.

20G or 22 G needles- 1 inch or 1½ inch long are usually best.


3. Intradermal injection


The needle gauge recommendation for Intradermal injection is 26G to 28G.


Needle Color Coding

ISO needle color coding


The color-coding of the needle hub indicates the needle diameter according to ISO 6009 standard.

Use needle hub color coding for the identification of the outside diameter of the hypodermic needles.

21G needles are the most commonly used for Venipuncture  or blood draws.

16G or 17G needles are commonly used for blood donation.


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