Brachial Plexus Injury: Causes, Symptoms & Treatment

A brachial plexus injury can affect the nerves that control movement and sensation in the shoulder, arm, and hand. Because these nerves connect the spinal cord to the upper limb, damage can lead to weakness, numbness, pain, or even loss of function. Some injuries are mild and heal with time, while others are severe and may require surgery and long-term rehabilitation.

If you are searching for information about brachial plexus injury, the main question is usually simple: what causes it, what symptoms should I watch for, and how is it treated? This article explains the condition clearly, from basic anatomy to recovery options.

What Is the Brachial Plexus?

The brachial plexus is a network of nerves that starts in the neck and travels through the shoulder into the arm and hand. These nerves control:

• Shoulder movement
• Elbow bending and straightening
• Wrist and hand movement
• Feeling in the arm, forearm, and hand

When these nerves are stretched, compressed, or torn, the result is a brachial plexus injury.

To understand how nerve structures work and why they can be vulnerable to trauma, the National Institute of Neurological Disorders and Stroke provides a helpful overview of brachial plexus injuries.

What Causes a Brachial Plexus Injury?

Brachial plexus injuries happen when the nerves are damaged by trauma, pressure, or inflammation. The cause often determines how severe the injury is and what kind of treatment is needed.

Common causes include:

1. Birth injury

In newborns, a brachial plexus injury can occur during delivery, especially if:

• The baby is large
• Delivery is difficult or prolonged
• Shoulder dystocia happens
• Forceps or vacuum assistance is used

This may lead to weakness in one arm, sometimes called obstetric brachial plexus palsy.

2. Motor vehicle accidents

Car, motorcycle, and bicycle accidents are a major cause in adults. A sudden force can stretch or tear the nerves.

3. Sports injuries

Contact sports such as football, wrestling, or rugby may cause the neck and shoulder to be forced apart, damaging the brachial plexus.

4. Falls

A hard fall onto the shoulder or neck can injure the nerve bundle.

5. Penetrating injuries

Stab wounds, gunshot wounds, or deep lacerations can directly damage the nerves.

6. Tumors or radiation

A tumor in the neck or shoulder region, or scar tissue from radiation therapy, can press on or injure the brachial plexus.

7. Inflammation or medical conditions

Some conditions cause nerve inflammation, including:

• Brachial neuritis
• Diabetes-related nerve damage
• Autoimmune disorders

Related nerve pain and inflammation can also be discussed in our internal guide on brachial neuritis.

Types of Brachial Plexus Injury

Brachial plexus injuries vary from mild to severe. Understanding the type helps guide treatment.

Stretch injury

The nerve is pulled but not torn. This is often the mildest type and may improve with time.

Rupture

The nerve is torn, but not where it attaches to the spinal cord.

Avulsion

The nerve is pulled away from the spinal cord. This is the most severe type and often causes permanent loss of function without surgical reconstruction.

Neuropraxia

This is temporary nerve dysfunction caused by stretching or compression. The nerve remains intact and often recovers fully.

Symptoms of Brachial Plexus Injury

Symptoms depend on which nerves are affected and how badly they are damaged. Some symptoms appear immediately, while others may develop over hours or days.

Common symptoms include:

• Weakness in the shoulder, arm, or hand
• Loss of movement in part or all of the arm
• Numbness or reduced sensation
• Burning, sharp, or electric shock-like pain
• Tingling or pins-and-needles feeling
• Drooping shoulder
• Muscle wasting over time
• Loss of reflexes
• Floppy arm in newborns

Severe symptoms may include:

• Complete paralysis of the arm
• Severe pain
• Horner syndrome in some upper nerve injuries, which may include:
• Drooping eyelid
• Small pupil
• Reduced facial sweating

If symptoms appear after trauma, medical evaluation should happen as soon as possible.

How Is Brachial Plexus Injury Diagnosed?

Diagnosis begins with a physical exam and medical history. A doctor will ask how the injury happened, what symptoms are present, and whether the arm can move normally.

Tests may include:

MRI

An MRI can show nerve damage, swelling, or compression.

CT myelography

This imaging test may help identify nerve root avulsion.

EMG and nerve conduction studies

These tests measure how well the nerves and muscles are working. They are especially useful a few weeks after the injury.

X-rays

X-rays may be used to check for fractures or shoulder injuries that occurred at the same time.

Brachial Plexus Injury Treatment

Treatment depends on the severity, cause, and type of nerve damage. Some injuries improve without surgery, while others need specialized intervention.

Non-surgical treatment

Mild brachial plexus injuries often respond well to conservative care.

Rest and protection

Avoiding further injury gives the nerves time to heal.

Pain management

Pain may be treated with:

• Over-the-counter pain relievers
• Prescription medications
• Nerve pain medications in some cases

Physical therapy

Physical therapy is important for maintaining:

• Joint flexibility
• Muscle strength
• Range of motion

Therapy can help prevent stiffness and contractures while the nerve heals. Early, guided movement is especially important because immobility can lead to stiffness even when the nerve itself is slowly recovering.

Occupational therapy

This helps patients regain the ability to perform daily tasks such as dressing, eating, and writing.

Bracing or splinting

Supports may be used to keep the arm in a functional position and reduce deformity.

Surgical treatment

Surgery may be needed if the injury is severe or there is no sign of recovery over time.

Surgical options include:

Nerve repair

If a nerve is torn, the surgeon may reconnect the ends.

Nerve grafting

A healthy nerve from another part of the body may be used to bridge the damaged area.

Nerve transfer

A less critical nerve is redirected to restore function in a more important muscle group.

Muscle or tendon transfer

If nerve recovery is not possible, surgeons may move muscles or tendons to improve movement.

Joint stabilization or reconstruction

In some cases, surgery may also address shoulder instability or deformity caused by weakness.

Because timing can affect outcomes, people with severe weakness or no recovery signs are often referred to a specialist early. In practice, treatment may also involve pain specialists, rehabilitation doctors, hand surgeons, or neurosurgeons depending on the pattern of injury.

Recovery and Prognosis

Recovery varies widely. Mild injuries may heal in weeks or months, while severe injuries can take much longer and may not recover fully.

Factors that affect recovery include:

• Type of nerve injury
• Age of the patient
• Time from injury to treatment
• Whether the nerve was stretched, torn, or avulsed
• Access to therapy and follow-up care

In general, injuries involving nerve stretching recover better than those involving tearing or avulsion. Early diagnosis and treatment improve the chances of a better outcome.

Recovery can also be slow because nerves regenerate gradually. Even when improvement occurs, strength and sensation may return in stages, and full recovery is not guaranteed in severe cases. Follow-up visits help track whether function is returning or whether further intervention is needed.

Can a Brachial Plexus Injury Heal on Its Own?

Yes, some can. Minor stretching injuries may improve without surgery, especially if the nerve was not torn. However, not all injuries heal naturally. If weakness, numbness, or pain persists, medical evaluation is important to determine whether the nerve is recovering.

This is why a watch-and-wait approach should always include proper follow-up. A clinician may repeat exams or testing to make sure the arm is improving and not quietly losing function over time.

When to See a Doctor

Seek medical care if you have:

• Arm weakness after an accident or fall
• Numbness in the shoulder, arm, or hand
• Severe or worsening pain
• Inability to move the arm normally
• Symptoms in a newborn’s arm after delivery

Emergency care is especially important after major trauma, as brachial plexus injury can occur along with fractures, spinal injuries, or blood vessel damage.

Complications of Brachial Plexus Injury

Without proper treatment, complications may include:

• Chronic pain
• Permanent weakness
• Loss of hand function
• Muscle atrophy
• Joint stiffness
• Shoulder instability
• Long-term disability

Early rehabilitation and monitoring can reduce the risk of these complications.

In newborns, untreated weakness can also interfere with developmental milestones if the arm is not being used normally. In adults, chronic nerve injury may affect work, sleep, sports, and everyday self-care.

Living With a Brachial Plexus Injury

Daily life can be challenging, especially if the dominant arm is affected. Recovery often requires patience and a combination of therapies. Many people benefit from:

• Ongoing physical therapy
• Assistive devices
• Pain management
• Regular follow-up with a neurologist or orthopedic specialist
• Emotional support if the injury affects work or independence

Children with brachial plexus injuries may also need long-term monitoring as they grow.

Practical adjustments at home and work can also help. Examples include using adaptive tools for dressing or writing, pacing activities to avoid overuse pain, and keeping therapy exercises consistent to preserve flexibility and strength.

Frequently Asked Questions

Is brachial plexus injury permanent?

Not always. Mild injuries may fully recover, but severe injuries such as nerve avulsion can cause lasting damage.

How long does recovery take?

Recovery may take weeks, months, or longer depending on the extent of the injury. Nerve healing is slow.

Does brachial plexus injury hurt?

It can. Some people have severe burning or shooting pain, while others mainly notice weakness or numbness.

Can physical therapy help?

Yes. Physical therapy is a major part of treatment and helps preserve movement and function.

Is surgery always needed?

No. Many mild injuries are treated without surgery. Surgery is usually considered when the nerve is torn or recovery is not happening.

Conclusion

Brachial Plexus Injury affects the nerves that control the arm and hand, and it can range from a mild stretch injury to a severe nerve tear or avulsion. The most common causes include birth trauma, accidents, sports injuries, falls, and penetrating wounds. Symptoms often include weakness, numbness, pain, and loss of movement.

Treatment depends on the severity of the injury. Some cases improve with rest, pain control, and therapy, while others require nerve surgery or reconstruction. Early diagnosis and timely care are key to the best possible recovery.

If you notice symptoms of a brachial plexus injury after trauma or in a newborn, prompt medical evaluation is important.