Lidocaine Injection: How It Works, Results and What to Expect

A lidocaine injection is a commonly used local anesthetic that temporarily blocks pain signals in a small, targeted area. It may be used before minor procedures, for certain painful musculoskeletal conditions, or as part of a diagnostic evaluation of pain.

Overview: What Is a Lidocaine Injection?

A lidocaine injection is a medical treatment that temporarily numbs a specific area of the body. Lidocaine is a local anesthetic, meaning it works near the injection site rather than making a person unconscious. It is often used to make procedures more comfortable, such as stitching a wound, removing a skin lesion, treating dental pain, or placing certain medical devices.

Doctors may also use lidocaine injections to assess or ease pain that appears to come from a joint, muscle, tendon region or nerve. In this setting, short-term pain relief can help clarify whether the treated structure is contributing to symptoms. The injection may be given alone or, in selected situations, alongside another medicine such as a corticosteroid.

Results depend on the reason for treatment, the injection location, the lidocaine formulation and individual factors. A clinician should explain the goal of the injection, likely duration of numbness and any activity restrictions before the procedure.

How Lidocaine Works in the Body

Nerves communicate pain, touch and temperature through small electrical signals. Lidocaine temporarily blocks sodium channels in nerve cells, reducing their ability to send these signals. As a result, the area supplied by those nerves becomes less sensitive or numb for a limited time.

The treatment affects sensation more than movement, although an injection close to a motor nerve can sometimes cause temporary weakness or heaviness in the nearby area. The effect is localized, but some lidocaine can enter the bloodstream. For this reason, clinicians choose the dose and technique carefully and monitor patients when appropriate.

Lidocaine does not repair an injured tissue or correct the underlying cause of chronic pain. Instead, it can provide a window of pain relief that allows a procedure to be performed, helps support rehabilitation, or gives useful diagnostic information. Depending on the clinical situation, a doctor may also evaluate related concerns such as back pain or joint-related symptoms.

Who May Be a Candidate for a Lidocaine Shot?

A lidocaine injection may be appropriate for people who need local numbing for a minor procedure or who have a clearly identified area of pain that may benefit from a diagnostic or therapeutic injection. The decision is individualized. It is based on symptoms, examination findings, medical history and, when needed, imaging or laboratory testing.

Before treatment, patients should tell the clinician about previous reactions to local anesthetics, heart rhythm problems, liver disease, seizure disorders, pregnancy or breastfeeding, and all medicines and supplements they use. Medicines that affect blood clotting are particularly important to discuss before injections into deeper tissues or near joints.

An injection may need to be delayed or avoided when there is an active skin infection at the intended site, unexplained fever, certain bleeding risks or a known serious allergy to the medication. A reported reaction in the past does not always mean true lidocaine allergy, so a doctor may ask detailed questions about what occurred.

• Minor skin procedures and wound repair
• Dental and oral procedures
• Selected nerve, muscle, joint or trigger-point pain evaluations
• Temporary pain control to support examination or rehabilitation

What Happens During the Procedure?

The exact process varies according to the injection purpose. First, the clinician confirms the treatment plan, checks relevant allergies and medicines, and explains expected sensations. The skin is cleaned with an antiseptic. For injections near deeper structures, ultrasound, fluoroscopy or another imaging method may be used to guide accurate needle placement.

When the needle enters, a person may feel a brief pinch, pressure or stinging. Lidocaine itself can sting for a few seconds before numbness develops. The clinician then injects the planned amount slowly and observes for discomfort or unusual symptoms. A simple skin injection may take only a few minutes, while image-guided pain procedures can take longer because of preparation and monitoring.

Afterward, the site may be covered with a small dressing. The care team will advise whether to rest, drive, eat normally or temporarily avoid exercise. For people receiving an injection to evaluate musculoskeletal pain, the clinician may ask them to note which movements are easier and how their pain changes over the following hours.

For appropriately selected patients, pain management may include targeted injections alongside physical therapy, activity modification and treatment of the underlying condition. An injection is usually one part of a broader care plan rather than a stand-alone solution for persistent pain.

How Long Do Lidocaine Injections Take to Kick In?

Lidocaine injections commonly begin to work within a few minutes. In many superficial areas, numbness starts in about 2 to 5 minutes, although the full effect may take slightly longer. The onset can vary according to the concentration used, blood flow in the tissue, the depth of injection and whether a medicine such as epinephrine is included to prolong the local effect.

For a procedure, the clinician usually tests the area before starting to ensure it is adequately numb. For a diagnostic pain injection, the patient may be asked to move the affected body part or perform a previously painful activity after the injection, if it is safe to do so.

If pain remains unchanged immediately after an injection intended to numb a suspected source, it does not automatically rule out every possible cause. Needle position, overlapping pain conditions and the complexity of nerve pathways can all affect the result. The treating clinician interprets the response in the context of the full assessment.

Does Lidocaine Reduce Inflammation or Just Pain?

Lidocaine primarily reduces pain and sensation; it is not an anti-inflammatory medicine. It works by interrupting pain signaling in nerves, not by directly reducing swelling or changing the immune processes that drive inflammation.

Some injections combine lidocaine with a corticosteroid. In those cases, lidocaine may provide more immediate numbing, while the corticosteroid is intended to reduce inflammation over a longer period when clinically appropriate. Not every painful condition is inflammatory, and corticosteroid injections are not suitable for everyone.

When an injection contains only lidocaine, any improved movement or comfort generally reflects temporary pain reduction. This can still be valuable: it may make an examination easier, help a person participate in prescribed rehabilitation, or clarify whether a particular anatomical area is involved in their symptoms.

How Long Will a Lidocaine Shot Last?

The numbing effect of a standard lidocaine injection often lasts about 1 to 2 hours, but it can be shorter or longer depending on the treated area, the dose, local circulation and the formulation. When epinephrine is added for specific clinical reasons, lidocaine may last longer because blood flow away from the injection site is reduced.

For pain-related injections, the duration of noticeable relief can be variable. Some people feel benefit only while the local anesthetic is active, while others experience a longer change in symptoms because reduced pain allows the area to settle or supports movement and rehabilitation. If lidocaine is combined with another medicine, the longer-term effect is related to that accompanying treatment rather than lidocaine alone.

Patients should protect a numb area from heat, sharp objects and accidental biting or pressure until normal sensation returns. A clinician can give more specific expectations based on the planned procedure and injection location.

How Do You Know if Lidocaine Is Working?

The clearest sign is reduced feeling in the targeted area. A person may notice that pain, touch, temperature or pinprick sensations are significantly dulled. During a minor procedure, the area should be comfortable enough for treatment, though pressure or pulling may still be felt.

When lidocaine is used to investigate pain, a meaningful reduction in the usual pain during a previously painful movement or activity may support the idea that the injected structure or nearby nerve pathway contributes to symptoms. It is helpful to report the degree of relief, how quickly it began and when it wore off.

Complete numbness is not necessary in every setting, and the expected effect differs between skin anesthesia, dental injections and deeper pain procedures. If the area is still painful, the clinician may reassess before proceeding rather than simply continuing treatment.

Recovery, Benefits and Possible Risks

Recovery after a lidocaine injection is usually straightforward. Mild tenderness, bruising or brief swelling at the injection site can occur and often settles within a day or two. Depending on the site, patients may be advised to rest temporarily, avoid strenuous activity, or wait until numbness has resolved before eating, walking without support or driving.

The main benefit is targeted, temporary pain relief without general anesthesia. This can make necessary procedures more tolerable and, in certain cases, provide useful information about the source of pain. Because it is short-acting, the response can usually be assessed relatively quickly.

Uncommon but important risks include bleeding, infection, nerve irritation, accidental injection into a blood vessel and allergic reaction. High blood levels of lidocaine can cause symptoms such as ringing in the ears, metallic taste, tingling around the mouth, dizziness, confusion, seizures or abnormal heart rhythms. These reactions are rare when injections are given correctly, but require prompt medical evaluation.

Acibadem International’s multidisciplinary specialists and JCI-accredited hospitals assess and treat pain conditions for international patients, including when image-guided procedures or coordinated rehabilitation are appropriate.

When to Seek Medical Care

Patients should contact the treating clinic if injection-site redness, warmth, swelling or pain is worsening; if fever develops; or if numbness, weakness or pain lasts longer than the clinician said to expect. New or progressive symptoms should not be assumed to be a normal effect of the injection.

Emergency medical care is needed for trouble breathing, facial or throat swelling, fainting, widespread hives, a seizure, severe dizziness, chest symptoms or a fast or irregular heartbeat. These may indicate a serious allergic or toxic reaction and should be assessed urgently.

For ongoing pain, repeated injections should be discussed with a qualified doctor rather than arranged solely on the basis of short-term relief. A comprehensive plan may include diagnosis, exercise-based rehabilitation, medicines or other treatments tailored to the underlying cause.

Frequently asked questions

Is a lidocaine injection painful?

There is usually a brief needle pinch and a short stinging sensation as lidocaine enters the tissue. The area often becomes numb within minutes, making the rest of a minor procedure more comfortable. The level of discomfort varies with the injection site and individual sensitivity.

Can someone drive after a lidocaine injection?

It depends on where the injection was given, whether another medicine or sedation was used, and whether there is temporary weakness or numbness. A person should not drive if they cannot safely control a vehicle or if their clinician has advised against it. The care team can provide procedure-specific instructions.

Can lidocaine injections be used for back or joint pain?

They may be used in selected cases to help identify or temporarily relieve pain from a particular muscle, joint region or nerve pathway. A careful clinical assessment is needed because back and joint pain can have several causes. Lidocaine alone is generally short-acting and is not a cure for the underlying condition.

What should be avoided while the area is numb?

A numb body part should be protected from burns, cuts, pressure and accidental injury. People should be cautious with hot drinks or food after mouth or dental anesthesia, and should avoid activities requiring normal strength or balance when a limb is numb. Normal activity can usually resume as sensation returns, unless the clinician gives different advice.

Are lidocaine injections safe during pregnancy?

Lidocaine is used in some medical situations during pregnancy, but the decision depends on the reason for treatment, injection site, dose and individual health factors. A pregnant person should tell the clinician about the pregnancy before any injection. The clinician can weigh expected benefits and potential risks and recommend the safest approach.

How often can lidocaine injections be given?

There is no single schedule that fits every use. Frequency depends on the reason for injection, the body area, the total amount of lidocaine used and whether other medicines are included. Recurrent pain should be reviewed by a clinician to ensure that treatment remains appropriate and that the underlying cause is being addressed.

References

• U.S. Food and Drug Administration
• MedlinePlus, U.S. National Library of Medicine
• American Society of Regional Anesthesia and Pain Medicine
• National Institute of Arthritis and Musculoskeletal and Skin Diseases

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.