Can an injection in the arm cause damage? An expert guide to risks and prevention

October 12, 2025 •

4 min read

While generally safe, an estimated annual incidence of nerve injury was 3.38 per 1,000,000 intramuscular injections in children under 15, with 8% involving the upper limb. This raises a critical question: can an injection in the arm cause damage? The answer is yes, though serious complications are rare and often preventable.

Quick Summary

Although rare, injections in the arm can cause serious damage, including nerve injuries like SIRVA and brachial neuritis, abscesses, and muscle fibrosis, primarily due to improper technique or needle placement.

Key Points

Rare but real risks: Serious complications from arm injections, such as nerve injury or infection, are rare but can occur due to improper technique or needle placement.
SIRVA: The most common type of serious arm injection injury is Shoulder Injury Related to Vaccine Administration (SIRVA), caused by injecting the substance into the shoulder joint instead of the deltoid muscle.
Nerve damage symptoms: Look out for immediate, sharp, or shooting pain during an injection, or delayed numbness, tingling, and weakness, which may indicate nerve trauma.
Preventive technique: Proper landmarking (at least two finger-widths below the acromion), correct needle length, and a 90-degree injection angle are crucial to minimize risks.
Patient vigilance: Monitoring the injection site for persistent severe pain, swelling, fever, or limited range of motion is important for early detection and treatment of complications.
Distinguishing symptoms: Understand the difference between mild, temporary post-injection soreness and signs of a more severe issue, which may require immediate medical attention.
Patient communication: Informing your provider of any concerning symptoms during or after the injection is a critical step in ensuring your safety and proper care.

Understanding the risks of arm injections

For most individuals, an injection in the arm is a routine, low-risk procedure. The most common side effects are temporary and limited to the injection site. These are typically part of the body's normal inflammatory and immune response. However, in rare instances, more significant damage can occur.

Common and mild side effects

Soreness and pain: A dull muscle ache is common and usually resolves within a day or two.
Swelling, redness, and itching: Localized inflammation can occur from the needle or the injected substance. Applying a cold compress can help.
Bruising: A blown vein, where the needle pokes through the vessel, can cause minor bleeding and bruising under the skin.
Minor bleeding: A small amount of bleeding is normal and stops with pressure.

Serious but rare complications

While uncommon, these more severe issues are what give concern to the question, "Can an injection in the arm cause damage?" They are often linked to improper administration or pre-existing conditions.

Nerve injury: Improper needle placement can directly damage a nerve, such as the radial or axillary nerve, or a nearby nerve plexus. The most common nerve injury associated with injections is Shoulder Injury Related to Vaccine Administration (SIRVA). SIRVA occurs when the injection is administered too high and the medication is injected into the shoulder joint or bursa instead of the deltoid muscle. This causes severe inflammation, chronic pain, and limited range of motion. Patients may also experience brachial neuritis, an inflammation of the nerves in the shoulder, which can cause intense pain and muscle weakness. Symptoms of nerve injury often include immediate, shooting pain, numbness, or tingling.
Infection and abscess formation: Bacterial or fungal infections can develop if aseptic techniques are not followed. This can lead to an abscess, a collection of pus that causes severe pain, redness, and swelling. Signs of a spreading infection, such as fever or red streaks extending from the site, require immediate medical attention.
Muscle fibrosis and contracture: Repeated intramuscular injections in the same site, particularly with certain medications, can lead to the fibrous replacement of muscle tissue. This can cause muscle hardening, weakness, and joint contracture, resulting in permanent disability.
Vascular injury: Inadvertently injecting into a blood vessel can cause damage. In rare cases, this can lead to tissue death (necrosis) or other vascular complications, such as gangrene, particularly with certain drug formulations.

Preventing injection-related injuries

Preventing complications from injections starts with proper technique and patient education. Medical professionals are trained to use appropriate injection sites and needles, but there are also steps patients can take.

The importance of proper technique

To minimize risks, especially for intramuscular injections in the arm's deltoid muscle, proper landmarking and technique are crucial.

Accurate landmarking: The deltoid muscle is identified using anatomical landmarks, including the acromion process (the bony point of the shoulder). The injection site should be at least two to three finger-widths below this point to avoid the shoulder capsule.
Needle selection: The needle length is chosen based on the patient's weight and body habitus to ensure the medication reaches the muscle without being too long or short.
Injection angle and speed: The needle should be inserted at a 90-degree angle with a quick, dart-like motion. The medication should be injected slowly and steadily.
Avoiding repeated sites: When multiple injections are needed over time, rotating the injection site helps prevent tissue damage and fibrosis.

Comparing injection complications


Symptom	Mild Complication (Common)	Severe Complication (Rare)
Onset	Hours to 2 days post-injection	Immediate or within 48 hours
Pain	Dull, manageable soreness	Severe, shooting, or burning pain
Swelling	Minor, localized swelling	Significant swelling, warmth, and spreading redness
Mobility	Slight, temporary limitation due to soreness	Decreased range of motion, weakness, or paralysis
Sensation	Localized itchiness or tenderness	Numbness, tingling, or electrical shock sensation
Systemic Symptoms	None	Fever, chills, or fatigue
Underlying Cause	Normal immune response	Improper needle placement, infection, or nerve damage
Treatment	Cold packs, OTC pain relievers	Physiotherapy, corticosteroids, surgery, or antibiotics
Resolution	Usually resolves in 1-2 days	Can be long-lasting or permanent without treatment

How to recognize and respond to potential injury

Patients should communicate any unusual sensations during or after an injection to their healthcare provider. Signs of a serious complication should prompt a call or visit to a medical professional.

Immediate warning signs:

A sudden, sharp, shooting pain during the injection.
Numbness or weakness in the arm or hand.
Unusual tingling sensations.

Delayed warning signs:

Persistent or increasing pain beyond 48 hours.
Significant swelling, redness, and warmth around the injection site.
Difficulty moving the arm or shoulder.
Signs of infection, such as fever or pus.

The critical role of patient communication

Patients can play an active role in their own safety. During an injection, it is recommended to relax the arm and inform the healthcare provider of any sharp or unusual pain immediately. Post-injection, monitoring for persistent or worsening symptoms is key for early detection of any complications. For more information on injection safety, the Centers for Disease Control and Prevention offers comprehensive guidance for healthcare providers and the public.

Conclusion

Can an injection in the arm cause damage? While the risk of serious damage is very low, it is not zero. Most post-injection discomfort is mild and temporary. However, improper injection technique can lead to rare but debilitating complications, such as nerve injury (like SIRVA), infections, or tissue damage. The key to prevention lies in using trained healthcare professionals who follow proper anatomical landmarking and injection procedures. By being aware of the risks, communicating effectively with your provider, and monitoring for warning signs, you can ensure a safe and successful injection experience.

Frequently Asked Questions

SIRVA stands for Shoulder Injury Related to Vaccine Administration. It occurs when a vaccine or other injection is administered too high on the arm, causing the needle to penetrate the shoulder joint capsule or bursa instead of the deltoid muscle.

Yes, mild soreness or pain in the arm is a common and expected side effect after an injection. It is caused by the immune system's response and inflammation in the muscle, and it typically resolves within a day or two.

Signs of nerve damage include immediate, sharp, or shooting pain during the injection, or later onset of numbness, tingling, weakness, or paralysis in the arm or hand.

An infection can occur if bacteria are introduced into the skin during the injection, typically due to a failure to maintain aseptic principles. A severe infection can lead to an abscess, which is a collection of pus.

While most injection injuries are temporary and resolve with proper treatment, permanent damage can occur in rare cases. This includes chronic nerve pain from nerve damage or permanent functional disability from severe muscle fibrosis.

Ensure the person giving the injection is a trained healthcare professional. You can also relax your arm completely and confirm the provider uses proper landmarking, ensuring the injection is not too high on the shoulder.

You should contact a healthcare provider immediately if you experience severe or persistent pain, significant swelling, signs of infection (fever, pus), or loss of sensation or movement in the injected arm.

Yes, chronic or improperly administered injections, especially with certain medications, can lead to muscle fibrosis, where healthy muscle tissue is replaced by fibrous tissue. This can result in permanent muscle hardening and contracture.