The radial artery is the main artery running along the thumb side of the forearm, and it’s one of the most clinically important blood vessels in the body, used routinely for checking your pulse, drawing arterial blood samples, and, increasingly, as the preferred access point for many cardiac catheterization procedures. This guide covers its anatomy and clinical significance.
This is general information, not medical advice.
Anatomy and course
The radial artery is one of the two main arteries of the forearm (the other being the ulnar artery), both branching from the brachial artery near the elbow. It runs along the lateral (thumb side) aspect of the forearm, initially covered by the brachioradialis muscle in the upper forearm, then running between the brachioradialis and pronator teres muscles, before passing more superficially between the brachioradialis and flexor carpi radialis tendons as it approaches the wrist. Near the wrist, it reaches the front of the distal radius bone, where the radial pulse, the pulse most commonly checked by placing two fingers on the wrist, is felt directly against the underlying bone.
Beyond the wrist, the radial artery passes through an area called the anatomical snuffbox (a small triangular depression visible on the back of the hand near the base of the thumb when the thumb is extended), where a distal pulse can also be felt, before entering the palm and contributing to the blood supply of the hand.
Clinical significance: checking your pulse
The radial pulse, felt at the wrist, is the most commonly checked pulse point in routine medical exams, since it’s easily accessible, generally reliable, and doesn’t require removing much clothing to access, unlike checking a pulse at the neck (carotid) or elsewhere.
Clinical significance: blood draws and arterial lines
The radial artery is a common site for drawing arterial blood gas samples (used to measure oxygen, carbon dioxide, and pH levels in the blood, particularly important in critically ill patients) and for placing an arterial line, a thin catheter inserted into the artery for continuous, real-time blood pressure monitoring in intensive care and during certain surgeries.
Clinical significance: cardiac catheterization
This is one of the more significant modern clinical uses of the radial artery: it’s increasingly the preferred access site for cardiac catheterization procedures (including coronary angiography and certain interventional procedures like stent placement), rather than the traditionally used femoral artery in the groin. Radial artery access is generally associated with fewer major bleeding complications and allows patients to be more comfortable and mobile sooner after the procedure compared with femoral access, which has driven a significant shift in interventional cardiology practice toward radial access over recent years where anatomically appropriate.
Why bone proximity matters for these procedures
Because the radial artery runs directly against the bone at the wrist (and again at the anatomical snuffbox), this bony backing is actually clinically useful: it makes the artery easier to compress against for achieving hemostasis (stopping bleeding) after a procedure, and it aids in accurate needle placement during radial artery access procedures, since clinicians can use ultrasound imaging alongside this anatomical landmark to confirm optimal puncture positioning.
Frequently asked questions
Why is the radial pulse checked at the wrist?
Because the radial artery runs directly against the wrist bone at that point, making the pulse easy and reliable to feel, and the location is easily accessible without needing to remove clothing, unlike checking a pulse elsewhere on the body.
What is the radial artery used for in heart procedures?
It’s increasingly the preferred access site for cardiac catheterization procedures like coronary angiography and stent placement, generally associated with fewer bleeding complications and quicker patient mobility compared with the traditional femoral artery access site.
What is the anatomical snuffbox?
A small triangular depression visible on the back of the hand near the thumb’s base when the thumb is extended; the radial artery passes through this area, and a pulse can be felt there too, sometimes used as an alternative access point.
Is the radial artery the same as the ulnar artery?
No, they’re the two separate main arteries of the forearm, both branching from the brachial artery; the radial artery runs along the thumb side, while the ulnar artery runs along the pinky side.
Why is radial access sometimes preferred over femoral access for cardiac procedures?
It’s generally associated with a lower risk of major bleeding complications and allows for faster patient mobility and comfort after the procedure, which has driven a significant shift toward radial access in interventional cardiology.