Why trigger points cause so much pain—and how you can relieve it

Knots in your muscles can arise from stress, anxiety, and even vitamin deficiencies. So how can they be treated?

A thermal image of the body from the neck to the waste. The area around the shoulder joint is red and orange, while the other parts of the body or blue.
This thermal image of the body highlights a region that contains common trigger points. We don’t know exactly how trigger points form but it is thought to be associated with chronic stretch or overload of the muscle that can lead to chemical changes that likely cause an over-sensitization in pain receptors.
Photograph by Giles Price, Nat Geo Image Collection
ByStacey Colino
May 08, 2024

You may not know the definition of a trigger point, but most people have experienced the ache or stab of pain that occurs when these locations on the body are touched or pressed.

Simply put, a trigger point is a discrete, hyperirritable nodule (like a “knot”) that is palpable in a taut band of muscle—and it can produce pain in a particular spot or in another part of the body. Recently, trigger points have been implicated in various conditions including myofascial pain syndrome (a chronic disorder involving the muscles and the surrounding connective tissue); tension-type headaches (particularly in women); migraine headaches; chronic neck pain; and low back pain.

While the formal term “myofascial trigger point” was coined in the 1950s, research investigating the underlying causes and effective treatments is relatively new.

That’s a positive development because trigger points are common—“85 percent of people will have myofascial pain at some point in their lives and often it involves trigger points,” says Shana Margolis, a physical medicine and rehabilitation physician at Northwestern Medicine in the Chicago area.

“Myofascial pain syndrome is kind of a big black box of pain disorders,” says Kiran Rajneesh, a neurologist and pain medicine physician at The Ohio State University Medical Center in Columbus. “There may be more to it than just a muscle issue. There could be underlying joint inflammation.”

No diagnostic test or way to image trigger points

Sometimes trigger points occur as a result of an injury, trauma, or repetitive strain. In other instances, they can result from poor posture (like sitting hunched over a computer) or excessive exercise. In each instance, a muscle nodule (or “knot”) develops. Trigger points are “generally caused when a muscle gets overloaded and it gets stuck contracted, and the fibers stay [closely] banded together,” Margolis explains.

For Hungry Minds

A new hypothesis suggests that trigger points may occur due to a “failure of protective regulatory mechanisms … that prevent excessive muscle activity or that prevent a potentially injurious accumulation of [calcium ions] within muscle cells,” according to a paper published last year in the International Journal of Molecular Science. 

“We don’t know exactly how trigger points form but it is thought to be associated with chronic stretch or overload of the muscle,” says Jennifer Hankenson, a physical medicine and rehabilitation specialist at Yale Medicine. “This chronic stress leads to chemical changes within the muscle that likely cause an over-sensitization in pain receptors. Trigger point pain is often out of proportion to the underlying injury, due to the pain sensitization process.”

In some instances, the pain can be associated with muscle dysfunction, muscle tightness or weakness, decreased flexibility, and a limited range of motion.

Because trigger points aren’t a medical condition unto themselves, there isn’t a diagnostic blood test, imaging technique, or tool that can be used to definitively identify them. The most commonly used technique is palpation of a suspected trigger point. If a clinician presses on a trigger point and the person feels pain or experiences a jump sign (such as wincing or groaning) or a reflex-like twitch in response to the pain, that’s considered an affirmative indication of a trigger point’s presence.

Active and passive trigger points vs. tender points

Different types of trigger points can be associated with body aches. An active trigger point is painful even if it isn’t touched, whereas a latent (or passive) trigger point is only painful when direct pressure is applied to it, explains Kemly Philip, a physical medicine and rehabilitation physician with UTHealth Houston and TIRR Memorial Hermann. “Direct pressure of an active trigger point can even stimulate an autonomic response of sweating, redness, or a feeling of lightheadedness.” Both types can cause referred pain, which is pain that radiates out from the trigger point.

In addition, satellite trigger points can occur when pain is spread over a considerable area—from the shoulder to the elbow, for example, or the back to the butt, Margolis adds. “Satellite trigger points typically go away when the primary trigger point resolves,” says Philip.

Research has also found that stress and anxiety may play a role in the development of muscle trigger points. And deficiencies in certain vitamins (such as B12) and minerals (such as zinc and magnesium) may contribute.

Distinguishing between trigger points and tender points, areas of tenderness in a muscle or around (but not in) joints, is also important. Tender points are typically a characteristic of fibromyalgia, a complex, chronic disorder that causes pain and tenderness throughout the body. Among the key differences: Trigger points often elicit a twitch response or jump sign when pressure is applied to them, whereas tender points don’t; trigger points can occur in any muscle while tender points occur in 18 specific locations that are symmetrical (on both sides of the body). Trigger points can cause referred pain, whereas tender points don’t.

“Making the distinction between trigger points and tender points is important because it guides us to what testing and treatments we want to do early on,” Rajneesh says. The presence of tender points warrants blood work to look for autoimmune conditions, which require different treatments than trigger points, he adds. Whether fibromyalgia is an autoimmune disease is a matter of ongoing debate.

Seeking relief

Various interventions may relieve trigger point-related pain but finding the right one is often a matter of trial and error. On the DIY end of the spectrum, the application of heat or ice (whichever feels better) or a topical analgesic cream, and use of over-the-counter non-steroidal anti-inflammatory drugs (like ibuprofen and naproxen) can ease the pain, Philip notes. Self-massage—using a massage gun, a tennis ball, or a foam roller on the afflicted area—also can be helpful.

Correcting your posture, your biomechanics (while walking or lifting things, for example), and your ergonomic set-up at work are essential too, Margolis says. “We tend to live in a head-forward, shoulder-forward world,” she says. “Focusing on correcting that is important.”

It’s also wise to pay attention to lifestyle habits. “If you sleep well, stay hydrated, and eat micronutrients [such as calcium, magnesium, zinc, and copper] that are anti-inflammatory, you’re going to heal faster and decrease muscle spasm,” Rajneesh says.

If these measures don’t provide sufficient relief within a couple of weeks, see your health-care provider about more intensive interventions. These may include physical therapy, manual therapies (such as the “spray and stretch technique” in which a coolant spray is used to numb the area before the muscle is gently stretched to improve range of motion), and electrical stimulation. Ultrasound, which “provides deep heat to increase blood flow to the area to get the muscle to relax,” also can help, Margolis says.

Farther along the spectrum of therapies, “trigger point injections, using steroids and/or local anesthetics [such as lidocaine], can release the trigger points,” Rajneesh says.

In addition, recent studies have shown that various physical treatments such as massage, acupuncture, electroacupuncture, and dry needling, can help relieve various forms of pain related to trigger points.

The goal with each of these treatments is to somehow release the trigger point so the taut band of muscle relaxes and the pain dissipates.

A newer therapy, platelet-rich plasma (PRP) injections—in which a person’s own platelets are injected into the painful region to stimulate healing and remodeling of the tissue—can help manage trigger points, Rajneesh says. The downside: “It’s expensive and considered experimental by insurance payors,” he adds, which means you’ll probably have to pay out of pocket for this.

However they’re treated, trigger points can be relieved. Unfortunately, they can also come back. If they do, you can travel down the road of discovery for therapeutic interventions again. “A specialist such as a physiatrist or pain specialist can often help you find the right treatment options to alleviate your pain and prevent reoccurrence,” Hankenson says.

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