What is the relationship between needle size and pain perception in medical procedures?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Smaller needle sizes are associated with reduced pain perception in medical procedures, with atraumatic needles and smaller diameters (23-24 G or less) showing a lower incidence of adverse events, including headache and back pain, as seen in the study 1. The relationship between needle size and pain is based on the diameter of the needle—larger gauge numbers indicate thinner needles that create smaller puncture wounds and stimulate fewer pain receptors. Key factors that influence pain perception include:

  • Needle type: atraumatic needles are associated with a lower incidence of adverse events, including headache and back pain 1
  • Needle diameter: smaller diameters (23-24 G or less) are associated with reduced pain perception 1
  • Patient position: sitting position may be associated with an increased risk of severe headache 1
  • Age: older patients (>65 years) may have a reduced risk of headache and back pain 1
  • Use of topical anesthetics and proper injection technique can further minimize discomfort, as suggested by other studies 1. For example, using sharp, well-manufactured needles, slow insertion at a 90-degree angle, and administering medication slowly can help reduce pain perception. Additionally, applying topical anesthetics like EMLA cream (lidocaine 2.5% and prilocaine 2.5%) 30-60 minutes before the procedure, and using room temperature injections instead of cold solutions, can also help minimize discomfort. It is also important to consider the patient's anxiety and fear of needles, and to use distraction techniques, breathing exercises, or other methods to manage anxiety and reduce pain perception, as suggested by the study 1. Overall, the use of smaller needle sizes, atraumatic needles, and proper injection technique, along with consideration of patient factors and anxiety, can help minimize pain perception and improve patient outcomes.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.