Radial Nerve: Function, Pathway, Symptoms and When to Seek Care
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is the radial nerve?
The radial nerve is a peripheral nerve in each arm that controls movement in parts of the upper arm, forearm, wrist and hand and carries sensation back to the brain. Pressure or injury can cause pain, tingling, numbness, weakness or difficulty lifting the wrist and fingers. Persistent symptoms or wrist drop should be assessed by a provider. [1]
What the research says
Surgery for a broken upper-arm bone can itself injure the radial nerve, and the surgical approach matters. A systematic review and meta-analysis of 9 studies (1,303 patients) found iatrogenic radial nerve palsy in 35 of 678 patients (5.2%) operated through the anterolateral approach and 69 of 497 (13.9%) through the posterior approach (OR 2.72, 95% CI 1.70–4.35); recovery rates did not differ significantly between approaches (Shon et al., Journal of Orthopaedic Science, 2023). [4]
The type of fixation also changes nerve-injury risk after a humeral shaft fracture. A systematic review and meta-analysis of 43 studies found a higher risk of iatrogenic radial nerve palsy with open plate fixation (ORIF) than with intramedullary nailing (RR 1.80) and than with minimally invasive plate osteosynthesis (RR 5.60). The authors noted that evidence on the best treatment remains moderate because randomized studies are limited. Treatment choice is an individual decision for the surgical team (Smolle et al., EFORT Open Reviews, 2022). [5]
What is the radial nerve?
The radial nerve is a peripheral nerve that supplies movement and sensation to parts of the arm, forearm, wrist and hand. There is one radial nerve in each arm. Its name comes from its relationship to the radius bone and radial artery in the forearm. To see how it fits into the wider nerve network, read our guide to the peripheral nervous system. [1]
Nerves act like communication cables. They carry electrical impulses between the brain and the rest of the body. These signals help muscles move and allow the body to register sensations such as touch, pain and temperature. [1]
The radial nerve works alongside other nerves that serve the arm, including the axillary, median, musculocutaneous and ulnar nerves. Each nerve has its own path and areas of influence. [1]
What does the radial nerve do?
The radial nerve has both motor and sensory roles. Its motor branches stimulate muscles that straighten the elbow, rotate the forearm and extend the wrist and fingers. [1]
The triceps muscles at the back of the upper arm help straighten the elbow. Other muscles in the outer forearm help rotate the forearm and extend the wrist and fingers, such as when the hand opens from a clenched position. [1]
The sensory branches carry touch, pain and temperature information from the back and outer side of the upper arm, the back of the forearm and the back of the wrist and hand nearest the thumb.
Role | Areas or actions involved |
Motor function | Straightening the elbow; rotating the forearm; extending the wrist and fingers. |
Sensory function | Touch, pain and temperature from parts of the upper arm, outer forearm, wrist and hand. |
Everyday tasks | Opening the hand, lifting objects, pinching, grasping and positioning the wrist. |
Where does the radial nerve travel?
The radial nerve is one of five branches that extend from the brachial plexus. The brachial plexus is a network of nerves that begins with nerve roots from the spinal cord in the lower neck and upper chest. These nerves pass beneath the collarbone and through the armpit. [1]
The radial nerve begins in the lower armpit. It then follows a winding course around the humerus, the long bone between the shoulder and elbow. Along the way, it sends smaller branches to muscles and skin in the upper arm. [1]
Near the outside of the elbow, the nerve passes through the radial tunnel, a narrow opening formed by bone and muscle. At the elbow, it separates into two major branches. [1]
The superficial branch
The superficial branch is sensory only. It travels from just below the elbow toward the wrist, hand and fingers. In the forearm, it runs alongside the radial artery. [1]
The deep branch
The deep branch travels between forearm muscles that help rotate the forearm. It stimulates muscles that extend the wrist, hand and fingers. This branch ends at the wrist. [1]
What can affect the radial nerve?
Radial-nerve problems may occur when the nerve is compressed, squeezed or injured along its path. The symptoms depend partly on where the nerve is affected and which branches are involved. [1]
Condition or problem | What it means |
Radial-nerve entrapment | The nerve is injured or compressed somewhere along its path, which may affect sensation, movement or both. |
Radial tunnel syndrome | The nerve is compressed in the radial tunnel near the elbow and forearm, potentially causing elbow-area pain and forearm or wrist weakness. |
Radial-nerve palsy | Weakness or paralysis may follow pressure on the nerve, sleeping on an outstretched arm, pressure from crutches or a humerus fracture. Wrist drop is a characteristic result. |
Wartenberg syndrome | Muscles compress the superficial sensory branch near the wrist, causing a type of mononeuropathy. |
A symptom does not identify the exact cause on its own. A healthcare provider can combine the location of symptoms, movement changes and an examination to decide what should happen next. For broader background on nerve disorders, see the NINDS overview of peripheral neuropathy and the CDC guide to diabetes and nerve damage. [1]
What are the symptoms of radial-nerve damage?
Symptoms can affect the upper arm, forearm, wrist or hand. Sensations may include pain, burning, itching, tingling and numbness. [1]
Movement changes may include weakness or paralysis in the arm, wrist or hand. Some people have difficulty straightening the elbow, wrist, hand or fingers. Grasping, pinching or picking up objects may become harder. [1]
Wrist drop means the wrist hangs limply and cannot be lifted. It is an important movement change to discuss promptly with a healthcare provider.
Symptom pattern | What a person may notice |
Sensory changes | Pain, burning, itching, tingling or numbness. |
Weakness | Reduced control in the arm, wrist, hand or fingers. |
Extension difficulty | Trouble straightening the elbow, wrist, hand or fingers. |
Hand-function changes | Difficulty grasping, pinching or picking up objects. |
Wrist drop | The wrist hangs down and cannot be lifted. |
When should you contact a healthcare provider?
Arrange a healthcare assessment for pain, numbness or weakness in the arm, wrist, hand or fingers, especially when the symptoms persist or interfere with daily tasks.
Prompt professional attention is also appropriate if you cannot extend the arm, wrist, hand or fingers, have trouble picking up items or develop wrist drop. These changes can affect function even when the cause is not yet clear.
A clinician may perform tests and assessments to determine whether the radial nerve is injured. Bring a short description of when the symptoms began, where they occur, what movements are difficult and whether the pattern is changing.
How can you support radial-nerve health?
Protecting radial-nerve health means avoiding prolonged pressure on the arms, managing conditions like diabetes, quitting smoking, staying active and reducing stress.
Avoid prolonged pressure on the armpits, elbows and arms. If you use crutches, take frequent breaks. [1]
Follow safety practices during high-impact activities because a humerus fracture can damage the radial nerve.
Work with a healthcare professional to manage chronic conditions that can damage nerves, including diabetes and high blood pressure. [1]
Seek help to quit smoking. Tobacco use can slow blood flow to nerves.
Aim for a weight that is healthy for you, stay physically active and choose nutritious foods. [1]
Reduce stress with healthy techniques such as meditation or walking. [1]
These measures support general nerve health, but they do not diagnose or treat a particular radial-nerve problem. New weakness, numbness or loss of movement still warrants professional assessment.
How does the radial nerve support everyday function?
The radial nerve is involved in movements people use throughout the day: straightening the elbow, rotating the forearm, lifting the wrist, opening the hand and extending the fingers. It also helps the brain receive sensory information from parts of the arm and hand.
Because its path is long and winding, symptoms may appear in more than one area. A problem near the armpit, upper arm, elbow or wrist can affect different combinations of sensation and movement. The pattern is useful information for a clinician, but it is not a diagnosis by itself.
Conclusion: A long, winding nerve with a big job
The radial nerve supports important movement and sensation in the upper arm, forearm, wrist and hand. It travels from the lower armpit around the humerus, passes near the outside of the elbow and divides into branches that serve muscles and skin. [1]
Pressure or injury may cause pain, tingling, numbness, weakness, difficulty extending the wrist or fingers, or wrist drop. If symptoms interfere with movement or hand function, contact a healthcare provider for an assessment. [1]
Noticing new radial-nerve symptoms? Write down where you feel them, which movements are difficult and how the pattern has changed, then bring that information to a healthcare provider. [1]
Frequently Asked Questions
Is the radial nerve a muscle?
No. The radial nerve is a peripheral nerve. It carries movement signals to certain muscles and sensory signals from parts of the arm, forearm, wrist and hand.
Is there a radial nerve in both arms?
Yes. There is one radial nerve in each arm.
What does the radial nerve control?
The radial nerve helps stimulate the triceps to straighten the elbow and supports forearm rotation and extension of the wrist and fingers. It also carries touch, pain and temperature sensations from parts of the arm and hand.
What does radial-nerve pain feel like?
Radial-nerve pain may feel like pain, burning, itching or tingling. Numbness can also occur. The exact pattern depends on where the nerve is affected.
Can radial-nerve problems affect grip?
Yes. Weakness or difficulty extending the wrist, hand or fingers can make grasping, pinching or picking up objects harder.
What is wrist drop?
Wrist drop describes a wrist that hangs limply and cannot be lifted. It can occur when the radial nerve is injured and should be assessed by a healthcare provider.
Can sleeping on an arm affect the radial nerve?
Pressure on the radial nerve while sleeping on an outstretched arm can contribute to radial-nerve palsy. Persistent weakness, numbness or movement loss should be assessed.
Can crutches put pressure on the radial nerve?
Pressure from crutches in the armpit can affect the radial nerve. Taking frequent breaks and using crutches safely can help reduce prolonged pressure.
What is radial tunnel syndrome?
Radial tunnel syndrome happens when the radial nerve is squeezed in a narrow passage near the outside of the elbow. It can cause pain around the elbow and weakness in the forearm or wrist.
Can a broken upper arm damage the radial nerve?
Yes. The radial nerve wraps around the humerus, so a break in that bone can injure it. New weakness, numbness or wrist drop after an arm injury needs prompt medical care.
Related Reading
Radial Tunnel Syndrome: Symptoms, Causes, Diagnosis, and Treatment explains radial nerve compression near the elbow and its treatment.
Understanding Humerus Fractures: Types, Symptoms, and Recovery covers upper arm fractures, which can injure the radial nerve.
Brachial Plexus Injury: Symptoms, Causes, and Treatment explains damage to the nerve network that gives rise to the radial nerve.
Understanding the Ulnar Nerve (Funny Bone) describes another major arm nerve and the problems it can cause.
References
Cleveland Clinic. Radial Nerve: What It Is, Function, Anatomy & Conditions. Cleveland Clinic. Last updated April 11, 2024. https://my.clevelandclinic.org/health/body/21617-radial-nerve
National Institute of Neurological Disorders and Stroke. Peripheral Neuropathy. NINDS. Last reviewed March 13, 2026. https://www.ninds.nih.gov/health-information/disorders/peripheral-neuropathy
Centers for Disease Control and Prevention. Nerve Damage. CDC. Updated May 15, 2024. https://www.cdc.gov/diabetes/diabetes-complications/diabetes-and-nerve-damage.html
Shon HC, Yang JY, Lee Y, et al. Iatrogenic radial nerve palsy in the surgical treatment of humerus shaft fracture: anterolateral versus posterior approach: a systematic review and meta-analysis. J Orthop Sci. 2023;28(1):244-250. PMID 34716068. https://doi.org/10.1016/j.jos.2021.09.015
Smolle MA, Bösmüller S, Puchwein P, et al. Complications in humeral shaft fractures: non-union, iatrogenic radial nerve palsy, and postoperative infection: a systematic review and meta-analysis. EFORT Open Rev. 2022;7(1):95-108. PMID 35073516. https://doi.org/10.1530/EOR-21-0097
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition.
It explains radial-nerve anatomy, function and symptom patterns in plain language. It is non-diagnostic and does not identify the cause of an individual’s symptoms or replace an examination by a qualified healthcare professional.
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