What Is a Trigger-Point Injection?

  • A trigger point is a tender area within a muscle that may feel like a knot or tight band. Pressure on the area may reproduce pain locally or cause pain to spread elsewhere.
  • A trigger-point injection involves placing a small amount of local anaesthetic directly into one or more painful trigger points. A small dose of corticosteroid may sometimes be added. The injections are commonly performed in muscles of the neck, shoulders, back or pelvic region.
  • The aim is to temporarily reduce pain and muscle spasm, allowing you to move more comfortably and participate in stretching, physiotherapy or rehabilitation. The treatment does not work for everyone and is not a permanent cure.

Is This the Right Treatment for Me?

Trigger-point injections may be considered when:

  • Your examination identifies one or more reproducible muscular trigger points.
  • Pain persists despite appropriate exercise, stretching or physiotherapy.
  • Pain is limiting movement, sleep or rehabilitation.
  • Reducing the pain temporarily may help clarify whether a particular muscle is contributing to your symptoms.

Your doctor will discuss the potential benefits, limitations, risks and alternatives with you. The decision to proceed will be made jointly by you and your doctor, and your consent will be obtained before treatment.

What Does “Off-Label” Steroid Use Mean?

Trigger-point injections may contain local anaesthetic alone or local anaesthetic combined with a small amount of corticosteroid.

Some corticosteroids are not specifically licensed by the manufacturer for injection into trigger points. This is known as off-label use. Many medicines are used off-label in specialist practice when the clinician considers this appropriate.

If a corticosteroid is proposed, your doctor will explain why it is being considered and discuss its potential benefits and risks before obtaining your consent.

What Happens During the Procedure?

  • You will be positioned comfortably so that the affected muscles can be examined.
  • Your blood pressure and pulse may be checked.
  • The painful areas will be identified by examination and, where appropriate, ultrasound.
  • The skin will be cleaned with an antiseptic solution.
  • A fine needle will be inserted into each selected trigger point.
  • Local anaesthetic, with or without corticosteroid, will be injected.
  • You may experience brief pressure, tightness, muscle twitching or discomfort. Please tell your doctor if you feel unwell or experience significant pain.

A cannula is not routinely required. The procedure usually takes approximately 10–20 minutes, depending on the number and location of trigger points being treated.

What Happens Afterwards?

You will be observed for a short period before going home. Temporary numbness, heaviness or weakness may occur if the local anaesthetic spreads to nearby muscles or nerves.

Please arrange for someone to take you home and do not drive for 24 hours after the procedure.

What Can I Expect During the Following Days?

  • Mild soreness, aching or bruising may occur for several days.
  • Your usual pain may temporarily flare before improving.
  • Keep the injection sites clean and dry for 24 hours.
  • Continue your regular pain medication unless advised otherwise.
  • Avoid strenuous activity on the day of treatment.
  • Resume normal activities gradually.
  • If the injection reduces your pain, use this opportunity to restart or progress your stretching, exercise or physiotherapy programme.

Pain relief may begin within hours because of the local anaesthetic. If corticosteroid is used, any additional benefit may take several days or occasionally longer to develop. The degree and duration of benefit vary, and some patients obtain no meaningful relief.

What Are the Possible Risks?

Most side effects are temporary. They may include:

  • Pain, tenderness or bruising at the injection site
  • Temporary worsening of pain
  • Temporary numbness or muscle weakness
  • Dizziness or faintness
  • Bleeding or haematoma
  • Infection
  • Lung injury or bowel injury risk, based on location of injections
  • An allergic reaction to the medication or antiseptic

Local anaesthetic toxicity is very rare. Tell your doctor immediately if you experience a metallic taste, tingling around your mouth, ringing in your ears, blurred vision, marked dizziness, muscle twitching or breathing difficulty during the procedure.

If corticosteroid is used, additional effects may include:

  • Facial flushing
  • Temporary sleep or mood disturbance
  • Temporary menstrual changes
  • A temporary rise in blood glucose, particularly in people with diabetes
  • A temporary fall in immunity
  • Skin discolouration, loss of pigmentation or dimpling at the injection site
  • Systemic steroid effects, which are more likely after repeated injections
  • Worsening of osteoporosis and increased risk of fractures
  • Rarely, new blurred or distorted vision requiring medical assessment

When Should I Seek Medical Attention?

Contact the clinic or seek urgent medical advice if you develop:

  • Increasing redness, warmth, swelling or discharge at an injection site
  • Fever, chills or feeling generally unwell
  • Persistent or worsening weakness or numbness
  • Severe pain that is continuing to worsen
  • New visual disturbance
  • Chest pain or breathlessness following an injection near the chest wall

Call 999 for severe breathing difficulty, collapse, seizures or signs of a serious allergic reaction.

When Can I Return to Work?

This depends on the location of the injections and the physical demands of your job. Many patients can return to light activities the following day. Please discuss heavy manual work or safety-critical duties with your doctor.

Before Attending

Please:

  • Bring an up-to-date list of your medications and allergies.
  • Continue your usual medicines unless specifically advised otherwise.
  • Inform the clinic if you take anticoagulant or antiplatelet medication.
  • Tell us if you have an infection, are taking antibiotics or feel unwell.
  • Tell us if you have diabetes or have previously reacted to local anaesthetic, corticosteroid or antiseptic.
  • Inform us if you are pregnant or think you may be pregnant.

Further information is available from the Faculty of Pain Medicine and Guy’s and St Thomas’ NHS Foundation Trust.

 

Please Tell Us If Your Health Has Changed

Please contact the clinic before your procedure if:

  • You have an infection, are taking antibiotics, feel unwell, or have redness or broken skin near the planned injection site. Your procedure may need to be postponed until the infection has resolved.
  • You have started taking anticoagulant or antiplatelet medication, including warfarin, heparin, apixaban, rivaroxaban or clopidogrel. Additional precautions may be required. Do not stop these medicines unless specifically instructed by your clinical team.
  • You have diabetes. Steroid injections may temporarily increase your blood glucose, so additional monitoring or adjustment of your diabetes medication may be required.
  • You have developed any new allergies or previously experienced a reaction to local anaesthetic, steroid, antiseptic or contrast dye.
  • You are pregnant, think you may be pregnant or are planning a pregnancy.
  • You are planning to travel abroad or fly within seven days of the procedure. Steroids can reduce your immunity temporarily. Depending on the treatment and destination, it may be safer to rearrange your appointment.