Radial Artery Pulse

The radial artery pulse is one of the most commonly examined peripheral arterial pulses. It is usually palpated on the anterior-lateral aspect of the distal forearm, immediately proximal to the wrist, where the radial artery lies relatively superficially and can be compressed against the underlying radius.

The radial artery is one of the two principal terminal branches of the brachial artery. It begins near the cubital fossa, descends along the lateral side of the forearm, passes around the lateral aspect of the wrist through the anatomical snuffbox, and then enters the hand to contribute substantially to the deep palmar arch.

Its accessible position at the wrist makes the radial pulse a practical landmark for assessing heart rate, rhythm, pulse character, and peripheral circulation.

Location of the Radial Pulse

The radial pulse is usually palpated on the anterior surface of the distal forearm on the thumb side of the wrist.

The artery lies lateral to the tendon of flexor carpi radialis and medial to the lateral border of the distal radius.

Surface Landmark

The distal radius and flexor carpi radialis tendon provide useful landmarks for locating the artery.

At this level the radial artery has relatively little soft tissue covering, allowing its pulsation to be transmitted readily to the fingertips.

Palpation Technique

1. Position the forearm comfortably with the palm facing upward or in a neutral position.
2. Identify the thumb side of the distal forearm.
3. Place the pads of the index and middle fingers just proximal to the wrist crease.
4. Apply gentle pressure over the artery lateral to the flexor carpi radialis tendon.
5. Adjust finger pressure until the pulsation is clearly felt.

Finger Position

The pulse is generally assessed using the pads of two or three fingers rather than the examiner's thumb.

Using multiple fingertips helps appreciate the arterial pulsation and allows small adjustments in position and pressure.

Relationship to the Radius

At the distal forearm, the radial artery lies over the anterior surface of the radius.

The firm underlying bone allows the vessel to be compressed gently, making the pulse easy to palpate.

Flexor Carpi Radialis Tendon

The tendon of flexor carpi radialis is an important landmark at the anterior wrist.

The radial artery lies immediately lateral to this tendon before curving dorsally around the wrist.

Brachioradialis Relationship

In much of the forearm, the radial artery is covered superficially by the brachioradialis.

Near the distal forearm, the artery becomes more superficial as the brachioradialis tendon moves toward its insertion on the distal radius.

Origin of the Radial Artery

The radial artery usually begins as a terminal branch of the brachial artery in the region of the cubital fossa.

Its companion terminal branch is the ulnar artery.

Course Through the Forearm

From its origin, the radial artery descends along the lateral aspect of the forearm.

Its course can be approximated from the region of the brachial artery bifurcation toward the palpable radial pulse at the distal radius.

Distal Course

After passing the conventional pulse site, the radial artery curves around the lateral aspect of the wrist.

It then passes onto the dorsolateral surface of the wrist through the anatomical snuffbox.

Anatomical Snuffbox

The radial artery crosses the floor of the anatomical snuffbox over the scaphoid and trapezium.

This represents another important surface relationship of the vessel, although the traditional radial pulse is usually assessed on the anterior distal forearm.

Entry into the Hand

After crossing the anatomical snuffbox, the radial artery passes into the hand between structures of the first intermetacarpal region.

It then contributes prominently to formation of the deep palmar arch.

Deep Palmar Arch

The deep palmar arch is formed primarily by the radial artery, with contribution from the deep branch of the ulnar artery.

It supplies deep structures of the palm and contributes to the arterial networks supplying the digits.

Major Surface Relationships

Structure	Relationship to Radial Artery
Flexor carpi radialis tendon	Artery lies lateral to tendon at distal forearm
Radius	Provides firm surface beneath pulse site
Brachioradialis	Overlies artery more proximally in forearm
Anatomical snuffbox	Artery passes through after leaving anterior wrist
Scaphoid and trapezium	Lie deep to artery in snuffbox

Superficial Branch of the Radial Nerve

The superficial branch of the radial nerve accompanies the radial artery through part of the forearm.

More distally, the nerve leaves the artery and passes toward the dorsolateral hand as a cutaneous sensory nerve.

Venae Comitantes

The radial artery is accompanied by paired deep veins, or venae comitantes, through much of its course.

These deep veins should not be confused with superficial veins visible beneath the skin of the forearm and wrist.

Pulse Rate

The radial pulse provides a convenient site for counting peripheral arterial pulsations and estimating the heart rate.

Each palpable pulse wave normally corresponds to a ventricular contraction that generates sufficient pressure to propagate through the arterial system.

Pulse Rhythm

Palpation can also provide information about whether the pulse rhythm feels regular or irregular.

Abnormal findings require interpretation in the context of the complete cardiovascular assessment.

Pulse Character

The radial pulse can provide information about the strength and contour of the arterial pulse wave.

Pulse character is influenced by cardiac output, arterial pressure, vascular resistance, arterial compliance, and other physiological factors.

Bilateral Comparison

Radial pulses can be palpated simultaneously on both wrists to compare timing and relative strength.

Marked asymmetry may indicate differences in arterial flow between the upper limbs and warrants appropriate clinical assessment.

Radial Pulse and Blood Pressure

The radial pulse may be used during palpatory estimation of systolic blood pressure.

Routine auscultatory blood pressure measurement, however, usually relies on the brachial artery rather than the radial artery.

Pulse Sites of the Upper Limb

Pulse	Typical Surface Location
Brachial	Cubital fossa, medial to biceps tendon
Radial	Anterior-lateral distal forearm
Ulnar	Anterior-medial wrist

Radial Versus Ulnar Pulse

The radial pulse is generally easier to palpate than the ulnar pulse because of its superficial position and favorable relationship to the distal radius.

The ulnar artery lies more medially at the wrist and can be more difficult to appreciate by palpation.

Clinical Significance

Routine Pulse Examination

The radial artery is the standard peripheral pulse site used in many routine examinations.

Its accessibility allows rapid assessment without exposing more proximal parts of the limb.

Assessment of Peripheral Circulation

The presence and relative strength of the radial pulse provide information about arterial perfusion reaching the distal upper limb.

Assessment may be combined with skin temperature, color, capillary refill, symptoms, and examination of other pulses.

Arterial Blood Sampling

The radial artery is commonly used for arterial blood sampling because of its accessible distal location.

Accurate knowledge of its surface course helps distinguish the artery from neighboring tendons and superficial structures.

Arterial Cannulation

The radial artery is frequently selected for arterial catheter placement when continuous arterial pressure monitoring or repeated blood sampling is required.

Its superficial location at the wrist makes it relatively accessible for this purpose.

Transradial Access

The radial artery can serve as an access route for selected endovascular and cardiac procedures.

Both conventional wrist access and distal radial access near the anatomical snuffbox may be used depending on the procedure and clinical circumstances.

Radial Artery Graft

The radial artery may be used as an arterial conduit in selected surgical procedures, including coronary artery bypass grafting.

Assessment of the arterial circulation of the hand is important when considering procedures that may alter radial artery flow.

Upper Limb Trauma

Injury to the forearm or wrist may compromise the radial artery.

Pulse examination forms one component of evaluating distal vascular status after trauma.

Collateral Circulation of the Hand

The hand receives arterial blood through contributions from both the radial and ulnar arteries.

These vessels communicate through the superficial and deep palmar arches and additional arterial connections.

Allen Test

The Allen test and modified versions have historically been used to assess collateral circulation of the hand before some radial artery procedures.

Clinical practice may also use other methods of vascular assessment depending on the procedure and setting.

Pulse Absence or Weakness

A weak or difficult-to-palpate radial pulse can result from physiological factors, low arterial pressure, local vascular disease, anatomical variation, technical factors, or other causes.

A pulse finding should therefore not be interpreted in isolation.

Anatomical Variation

The radial artery can show variation in its origin, course, branching, and superficial position.

A high origin of the radial artery or an unusually superficial course may alter the expected surface anatomy.

Superficial Radial Artery Variation

In some individuals, the radial artery follows a more superficial course than usual.

Recognizing vascular variation is important during venipuncture, cannulation, surgery, and other procedures involving the forearm and wrist.

Radial Pulse Versus Radial Artery in the Snuffbox

Feature	Traditional Radial Pulse Site	Anatomical Snuffbox
Location	Anterior-lateral distal forearm	Dorsolateral wrist
Underlying structures	Distal radius	Scaphoid and trapezium
Main use	Routine pulse palpation	Distal radial artery localization
Tendon relationship	Lateral to flexor carpi radialis	Between thumb extensor tendon boundaries

Key Surface Anatomy Features

Feature	Key Point
Pulse location	Anterior-lateral distal forearm
Side of wrist	Thumb side
Key tendon	Flexor carpi radialis
Artery position	Lateral to flexor carpi radialis tendon
Underlying bone	Radius
Origin	Terminal branch of brachial artery
Distal course	Passes through anatomical snuffbox
Hand contribution	Major contributor to deep palmar arch
Main examination use	Pulse rate, rhythm and peripheral circulation
Clinical importance	Arterial sampling, cannulation and transradial access

Anatomical Importance

The radial artery pulse is one of the most accessible and useful landmarks in upper limb surface anatomy. The pulse is typically located on the anterior-lateral distal forearm, just proximal to the wrist, where the artery lies lateral to the flexor carpi radialis tendon and can be compressed gently against the radius.

The vessel can be followed anatomically from its origin as a terminal branch of the brachial artery through the lateral forearm, around the wrist, and into the anatomical snuffbox. It then enters the hand and contributes substantially to the deep palmar arch.

Its superficial distal position explains the widespread use of the radial artery for routine pulse examination, arterial blood sampling, arterial cannulation, and vascular access. Its surface relationships with the radius, flexor carpi radialis tendon, brachioradialis, and anatomical snuffbox provide reliable landmarks for locating the vessel.