This factsheet is for people who are having a trigger point injection, or who would like information about it.
A trigger point injection is used to treat a trigger point in a muscle by relieving pain and helping to restore function of the muscle.
Your care will be adapted to meet your individual needs and may differ from what is described here. So it’s important that you follow your doctor’s advice.
- What is a trigger point?
- About trigger point injections
- Diagnosis of trigger points
- What are the alternatives to trigger point injections?
- Preparing for your trigger point injection
- About the procedure
- What to expect afterwards
- Recovering from your trigger point injection
- What are the risks?
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
Trigger point injections are used to treat a trigger point by reducing the pain and restoring function in your muscle.
You will usually be given an injection of local anaesthetic, sometimes in combination with a steroid or another drug, directly into your trigger point. Other drugs that are sometimes used include a non-steroidal anti-inflammatory drug called diclofenac and a drug called botulinum toxin type A.
There are several other techniques that may be used. Sometimes the local anaesthetic is injected into the skin or tissue over your trigger point, instead of directly into your muscle. Sometimes a needle with no medication inside is inserted directly into the trigger point. This is called dry needling.
Diagnosis of trigger points
Your doctor will ask about your symptoms and examine you. He or she may apply pressure to certain points on your body, to find any trigger points.
Your doctor may also ask you to have a blood test.
What are the alternatives to trigger point injections?
Trigger points can sometimes be treated with spray and stretch technique or ultrasound therapy.
Spray and stretch technique involves a cooling substance being sprayed over your muscle, which allows the muscle to be stretched.
Ultrasound therapy uses sound waves to apply heat to the painful area. Heat helps to improve your circulation and reduce the pain in your muscles.
If you have fibromyalgia or myofascial pain, stretching and massage can be very helpful. Reducing your stress levels and getting enough good quality sleep can also help to reduce your symptoms.
Sometimes, your doctor may prescribe anti-inflammatory drugs or antidepressants.
Preparing for your trigger point injection
Trigger point injections are usually done as a day case procedure in hospital.
Your doctor will explain how to prepare for your injection.
If you have a bleeding or blood clotting disorder, you may not be able to have a trigger point injection. This is because you may have a higher risk of bruising or bleeding. Let your doctor know if you have any bleeding or blood clotting disorders.
You must also let your doctor know if you’re pregnant, or if you think that you might be.
You will usually be advised not to take aspirin for at least three days before the injection.
About the procedure
You may be given a sedative before the procedure. This will relieve anxiety and help you to relax.
You will be put into a comfortable position. Your doctor will find your trigger point by pinching it between his or her thumb and finger. He or she will then clean the skin over the trigger point.
Your doctor will usually inject a local anaesthetic, sometimes in combination with a steroid or another drug, directly into your trigger point.
Alternatively, the local anaesthetic may be injected into the skin or tissue over your trigger point, instead of directly into your muscle, or there may be no medication inside the needle.
You may feel a sharp pain, twitch or unpleasant feeling as the needle enters your muscle.
The injection may be repeated several times, until your muscle is no longer tight or twitching.
Once the needle has been removed, your doctor will apply pressure to the area for about two minutes. He or she may then cover the area with a dressing.
What to expect afterwards
You will usually be able to go home when you feel ready. Try to arrange for someone to drive you home. Try to have a friend or relative stay with you for the first 24 hours.
Sedation temporarily affects your co-ordination and reasoning skills, so if you have had a sedative 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.
The area where you had the injection may feel sore afterwards. The pain should go away within about three or four days.
Recovering from your trigger point injection
After a trigger point injection you may need to exercise or stretch the affected muscle. Your doctor will be able to give you further advice on this.
Try to remain active and use your muscle as you normally would during the week after your injection. But don’t do any strenuous activity, particularly during the first three or four days after the injection.
What are the risks?
Trigger point injections are commonly performed and generally safe. However, in order to make an informed decision and give your consent, you need to be aware of the possible side-effects and the risk of complications of this procedure.
Side-effects are the unwanted but mostly temporary effects you may get after having the procedure.
You may have some pain and bruising around the area where the needle was inserted.
This is when problems occur during or after the procedure. Most people aren’t affected.
Complications specific to a trigger point injection are listed here.
- You could faint.
- You could get a skin infection in the area where the needle was inserted.
- You could develop a hematoma. This is when blood leaks out of a blood vessel and accumulates within your tissue or an organ.
- If you have a trigger point injection into a muscle near your rib cage, you could get a pneumothorax. This means that air has leaked from your lungs into your chest cavity.
- If you have trigger point injections into the same muscle too often, they can damage your skin and the muscle around the affected area.
The exact risks are specific to you and differ for every person, so we haven’t included statistics here. Ask your doctor to explain how these risks apply to you.