Understanding the Ulnar Artery

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026

The ulnar artery is one of the two primary blood vessels in the forearm, supplying oxygen-rich blood to the hands, wrists, and fingers. [1] Located along the pinky side of the arm, it is essential for fine motor function and sensory health. Repetitive trauma can lead to serious conditions like ulnar artery thrombosis. [1]

Quick Answer: What is the ulnar artery?

The ulnar artery is a major forearm blood vessel that carries oxygenated blood from the elbow to the hand. [1] A branch of the brachial artery, it runs along the forearm's pinky-finger side. [1] Its main role is supplying circulation to the muscles, bones and nerves of the forearm and hand, supporting sensation and movement in the fingers and palm.

What the research says

• Hypothenar hammer syndrome is a recognized cause of hand ischemia. A review advises considering it in people who use the hypothenar region as a hammer at work or in recreation; diagnosis relies on examination (including the Allen test), plethysmography, and duplex ultrasound, with angiography as the traditional gold standard. Hand protection and smoking cessation apply to all patients, while the best treatment, including surgery, remains controversial because of limited data (Schröttle et al., VASA, 2015) [2].

• Surgery helps many patients, but bypass grafts can clot. In 19 patients who had the damaged ulnar artery segment replaced with a vein graft (mean follow-up 7 years), 47% had complete resolution of symptoms, 42% improved, and 11% were unchanged; bypass patency was 63% (Piessat et al., Hand Surgery and Rehabilitation, 2023) [3].

• A single blunt injury can also cause it. A case report described distal ulnar artery thrombosis after one blunt trauma to the hand, treated by removing the clotted segment; the authors note that thrombosis from chronic trauma (hypothenar hammer syndrome) is the more frequent cause, and this is low-level evidence from a single case (Karaarslan et al., Case Reports in Orthopedics, 2014) [4].

Anatomy of the Ulnar Artery

The ulnar artery originates just below the bend of the elbow as one of the two main branches of the brachial artery, with the radial artery being the other. It travels down the medial side of the forearm, following the path of the ulna bone. At the wrist, the artery enters the palm through a specialized passage called Guyon’s canal, where it eventually forms the superficial palmar arch. [1]

Branch Name	Primary Function
Common Interosseous Artery	Supplies blood to the deep structures of the forearm.
Superficial Palmar Arch	The main network of arteries supplying the palm and fingers. [1]
Carpal Branches	Provide circulation to the bones and joints of the wrist. [1]
Ulnar Recurrent Arteries	Supply the pronator teres muscle, aiding in arm rotation. [1]

Figure 1: The anatomical course and major branches of the ulnar artery.

Circulatory Function

As a vital component of the circulatory system, the ulnar artery ensures that the tissues of the upper limb receive the oxygen and nutrients required for optimal performance. Its distribution network is extensive, reaching into the smallest capillaries of the fingertips.

The artery is responsible for supplying oxygen-rich blood to:

• The muscles of the forearm involved in movement and rotation. [1]

• The ulnar nerve, which facilitates sensation and motor control in the hand. [1]

• The complex network of bones and joints that form the wrist. [1]

• The fingers, particularly the fourth (ring) and fifth (pinky) digits.

Figure 2: Blood distribution and circulatory role of the ulnar artery.

Common Conditions and Symptoms

The ulnar artery is susceptible to injury, particularly from repetitive physical stress. The most common condition associated with this vessel is ulnar artery thrombosis, also known as hypothenar hammer syndrome. [1] This occurs when a blood clot forms within the artery due to sudden impact or frequent repetitive movements, such as using the palm of the hand as a hammer. [1] [2]

Common symptoms of ulnar artery dysfunction include:

• Blanching: A loss of color in the pinky or ring finger due to restricted blood flow. [1]

• Numbness and Tingling: A "pins and needles" sensation in the hand or fingers. [1]

• Wrist Pain: Persistent discomfort in the ulnar side of the wrist. [1]

• Loss of Grip Strength: Difficulty grasping or holding objects securely. [1]

If you experience persistent numbness, unexplained tingling, or a visible loss of color in your fingers, it is essential to consult a healthcare provider to evaluate your circulatory health.

Caring for Your Circulatory System

Maintaining the health of the ulnar artery involves general cardiovascular wellness and protecting the hands from repetitive trauma. Lifestyle choices that support overall circulation, such as maintaining a healthy weight, controlling blood pressure, and avoiding tobacco use, are fundamental. [1] Additionally, individuals whose work involves repetitive hand movements should use proper ergonomic tools and protective equipment to prevent physical damage to the artery. [2]

Figure 3: Strategies for protecting and maintaining ulnar artery health.

Conclusion

The ulnar artery is a cornerstone of hand and forearm health, providing the essential circulation needed for everyday tasks. From supporting fine motor skills to ensuring sensory feedback, its role is indispensable. By understanding the risks of repetitive trauma and adopting a heart-healthy lifestyle, individuals can protect their circulatory system and ensure the long-term vitality of their hands and fingers.

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Frequently Asked Questions

What is the ulnar artery?

The ulnar artery is one of the two main arteries in the forearm that supplies oxygen-rich blood to the hand, wrist, and fingers.

Where is the ulnar artery located?

The ulnar artery starts just below the elbow and runs along the inner side of the forearm, closest to the pinky finger, before entering the hand.

What is the difference between the ulnar and radial arteries?

The ulnar artery runs along the pinky side of the forearm, while the radial artery runs along the thumb side.

What is hypothenar hammer syndrome?

Hypothenar hammer syndrome is a condition where a blood clot forms in the ulnar artery, often caused by repetitive trauma to the palm of the hand.

What are the symptoms of a blocked ulnar artery?

Symptoms include numbness, tingling, wrist pain, loss of grip strength, and a loss of color in the pinky or ring fingers.

Does the ulnar artery pass through the carpal tunnel?

No, the ulnar artery passes through Guyon’s canal in the wrist, not the carpal tunnel.

How does smoking affect the ulnar artery?

Smoking can damage the lining of blood vessels and increase the risk of blood clots and arterial disease throughout the body.

What is the superficial palmar arch?

The superficial palmar arch is a network of arteries in the palm, primarily supplied by the ulnar artery, that distributes blood to the fingers.

Can repetitive hammering damage the ulnar artery?

Yes, repetitive impact on the palm can cause ulnar artery thrombosis, a serious circulatory condition.

When should I see a doctor for hand numbness?

You should consult a healthcare provider if you experience persistent numbness, tingling, or a loss of strength in your hands or fingers.

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Related Reading

Radial Artery: Anatomy, Function, Uses and When to Seek Care explains the forearm's other main artery and its medical uses.

Understanding the Ulnar Nerve (Funny Bone) describes the nerve that runs alongside the ulnar artery.

What Is Raynaud’s Disease? A Plain-Language Guide to the Cold-Fingers Condition, Its Causes, and Its Treatment explains why fingers turn white or blue in the cold.

Peripheral Artery Disease (PAD): Symptoms, Causes, Diagnosis & Treatment Options explains narrowed limb arteries, symptoms and treatment options.

References

1. Cleveland Clinic. Ulnar Artery. Cleveland Clinic. Last updated June 14, 2022. https://my.clevelandclinic.org/health/body/23436-ulnar-artery

2. Schröttle A, Czihal M, Lottspeich C, et al. Hypothenar hammer syndrome. VASA. 2015;44(3):179-185. PMID 26098321. https://doi.org/10.1024/0301-1526/a000427

3. Piessat C, De Almeida YK, Athlani L. Hypothenar hammer syndrome: outcomes after ulnar artery reconstruction with autologous vein graft. Hand Surgery and Rehabilitation. 2023;42(3):203-207. PMID 36893887. https://doi.org/10.1016/j.hansur.2023.02.008

4. Karaarslan AA, Karakaşlı A, Mayda A, et al. Traumatic distal ulnar artery thrombosis. Case Reports in Orthopedics. 2014;2014:983160. PMID 25276455. https://doi.org/10.1155/2014/983160

Medical disclaimer

The information provided in this article is for educational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.