Trigger point injections

What is a trigger point?

A trigger point is a specific spot in your muscle that is painful and tender when pressure is applied.

If you have a trigger point, you may not be able to use your muscle as you would usually, or it may be weaker than normal. Trigger points can also cause 'referred' pain - pain and discomfort in other areas of your body.

Trigger points are associated with a number of conditions, particularly chronic (long-lasting) musculoskeletal disorders.

It's common to have trigger points if you have fibromyalgia or myofascial pain syndrome. Fibromyalgia is a long-lasting condition that causes pain and stiffness in your muscles, ligaments and tendons. Myofascial pain syndrome is a common disorder that causes pain, stiffness and spasm in your muscles.

About trigger point injections

Your GP may suggest having a trigger point injection if you have pain and stiffness in a specific spot in your muscle (known as a trigger point). A trigger point can be caused by injury or a long-term musculoskeletal disease, such as fibromyalgia or myofascial pain syndrome. The muscles most commonly affected by trigger points are in your neck, shoulder and pelvic area.

Trigger point injections can help reduce pain and stiffness and allow you to move the affected muscle more easily. The effects of a successful trigger point injection can last from a few weeks to several months. They are usually given by a doctor who specialises in pain management.

Medicines used most often in trigger point injections include local anaesthetic (to reduce feeling) and steroids (to reduce swelling) into the injected muscle. Sometimes a non-steroidal anti-inflammatory medicine (eg diclofenac) or botulinum A toxin (eg Botox) are used.

What are the alternatives to trigger point injections?

Trigger point injections act only in the area that has been injected. Muscle pain can sometimes be treated with antidepressants, steroid tablets, painkillers, medicated spray, heat therapy, transcutaneous electrical nerve stimulation (TENS), acupuncture, massage or physiotherapy.

Your doctor may suggest using a combination of treatments to give you a pain-free 'window' during which you can have physiotherapy to help stretch your muscle. Speak to your doctor about which treatment is most suitable for you.

Preparing for a trigger point injection

Your doctor will explain how to prepare for your procedure. You may have the injection in a hospital or at your doctor’s surgery. This will depend on the trigger point that is being injected.

You shouldn’t take any aspirin for at least three days before the injection. You must also let your doctor know if you have any bleeding or blood clotting disorders, or if you’re pregnant or think you might be.

Your doctor will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

What happens during a trigger point injection

You may be offered a sedative before the procedure. This relieves anxiety and helps you to relax.

Your doctor will find the trigger point by applying pressure with his or her thumb and finger to the affected area. He or she will then clean the skin over the trigger point with a sterile wipe.

The injection is put directly into the trigger point and usually contains a local anaesthetic, sometimes in combination with a steroid or another medicine. Alternatively, the local anaesthetic may be injected into the skin or tissue over the trigger point, instead of directly into your muscle. Or there may be no medication inside the needle (this is called dry needling). You may feel a sharp pain, twitch or unpleasant feeling as the needle goes into your muscle.

The injection may be repeated several times until your muscle is no longer tight or twitching.

Afterwards, your doctor will apply pressure to the area for about two minutes and then cover it with a dressing.

What to expect afterwards

After a local anaesthetic it may take several hours before the feeling comes back into the treated muscle. Take special care not to bump or knock the area.

You will usually be able to go home when you feel ready. Before you leave, your doctor may test how much movement you have in your muscle and give you some exercises to do at home.

If you have had sedation, this may temporarily affect your co-ordination and reasoning skills, so you must not drive, drink alcohol, operate machinery or sign legal documents for 24 hours afterwards. If you’re in any doubt about driving, contact your motor insurer so that you’re aware of their recommendations, and always follow your doctor’s advice.

You will need to arrange for someone to drive you home. Try to have a friend or relative stay with you for the first 24 hours after your trigger point injection.

Recovering from a trigger point injection

You will feel some discomfort as the local anaesthetic wears off. The pain may initially feel worse than before you had the injection, but this is normal.

If you need pain relief, you can take over-the-counter painkillers such as paracetamol or ibuprofen. Always read the patient information that comes with your medicine and if you have any questions, ask your pharmacist for advice.

If you’re having physiotherapy, your physiotherapist may encourage you to move and stretch the affected muscle. Alternatively, you may be advised to keep movements to a minimum for a day or two, so it’s important to follow your doctor’s or physiotherapist’s advice.

Most people don’t have any problems after a trigger point injection, but you should contact your GP if you have a high temperature or increasing pain and swelling in the muscle that doesn’t settle within 24 hours.

What are the risks?

As with every procedure, there are some risks associated with trigger point injections. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your doctor to explain how these risks apply to you. 

Side-effects

Side-effects are the unwanted but mostly temporary effects you may get after having the procedure. The main side-effect of a trigger point injection is pain and swelling – this usually settles within three to four days.

Complications

Complications are when problems occur during or after the procedure. Complications of trigger point injection can include:

  • infection – you may need treatment with antibiotics
  • bruising under the skin – the needle can damage a blood vessel in the area and cause blood to pool in the muscle (this is called a hematoma)
  • loss of sensation – the needle can damage a nerve in the area and cause numbness
  • muscle weakness – repeat injections can damage the muscle and cause weakness

If you have a trigger point injection in your chest wall, there is a risk that the needle can puncture your lung (this is called a pneumothorax). Your doctor will advise you if this may be a potential complication of the procedure.

Are trigger point injections the same as acupuncture?

Answer

No, trigger point injections and acupuncture are different procedures, although both can help to reduce pain in different areas of your body. Acupuncture involves puncturing your skin with needles in defined points to relieve pain. Trigger point injections involve injecting medicines into a painful muscle.

Explanation

Acupuncture is a complementary therapy that typically involves puncturing the skin with needles in defined points to relieve pain and reduce the symptoms of certain conditions. The needles used for acupuncture are very fine and solid. They are not used to inject medicines into the skin. Acupuncture needles may be inserted into your skin and then removed straight away, or left in place for around 30 minutes. This depends on the type of treatment you're having. Acupuncture may be done by a doctor, physiotherapist or acupuncturist.

Trigger point injections are given by a doctor who specialises in pain management. They usually involve injecting a local anaesthetic and a steroid directly into a trigger point. Sometimes a needle with no medication may be used. This is called dry needling.

If the trigger point injection doesn't work, how soon can I have another one?

Answer

You won't usually be able to have another trigger point injection until the soreness around the injection area has gone away. This usually takes around three to four days.

Explanation

Your doctor will be able to advise you how long to wait before having another trigger point injection. Trigger point injections shouldn’t be repeated too often, as this can cause damage to your skin and the muscle around the affected area. If you have had two or three injections into a trigger point and they haven’t been successful at relieving your symptoms, further injections aren’t usually recommended.

Can trigger point injections provide long-term pain relief?

Answer

A trigger point injection can be used to give temporary relief if one or two places are particularly painful. However, trigger point injections alone don’t usually lead to long-term improvement in pain.

Explanation

A trigger point injection is mainly used to manage your symptoms and not to treat the underlying cause of the condition. The injection can help to ease pain and swelling so that it’s easier to move the affected muscle.

Trigger point injections are usually given along with other therapies to help treat or manage the condition causing these symptoms. For example, your doctor will usually recommend physiotherapy to help stretch and relax the muscle.

If you still have muscle pain and stiffness after a course of trigger point injections, speak to your doctor about alternative treatments.