Pain that improves and then returns can be frustrating. A stiff back after sitting, recurring shoulder discomfort, or knee pain after exercise may interfere with sleep, work, and daily activities. But why does pain keep coming back, even after rest or treatment?

Recurring pain can have several causes, including repetitive physical stress, joint problems, incomplete rehabilitation, and changes in how the nervous system processes pain. Understanding these factors is essential for long-term pain management. Laser therapy, particularly photobiomodulation therapy (PBMT), is one non-invasive approach being studied for selected pain conditions. However, its effectiveness varies, and it should not replace appropriate medical care.

1. Why Does Pain Keep Coming Back?

1.1 Common Causes of Recurring Pain

Recurring pain often develops when physical demands repeatedly exceed the body's recovery capacity. Prolonged sitting, repetitive movements, muscle overload, and returning to exercise too quickly may contribute to recurring discomfort.

Joint conditions, including osteoarthritis and tendon disorders, can also cause symptoms that fluctuate with activity. Rest may temporarily relieve discomfort without resolving the underlying problem.

Inflammation is not the only explanation. Some conditions involve nerve dysfunction or increased nervous system sensitivity, meaning pain may persist even after the original injury has healed.

1.2 Chronic Pain and Nervous System Sensitivity

Pain is not simply a direct measure of tissue damage. In some people, the nervous system becomes more sensitive, amplifying signals that would otherwise produce less discomfort.

This process, known as sensitization, may help explain why certain movements remain painful after an injury has improved. Chronic pain can also involve multiple overlapping mechanisms, including tissue-related pain, neuropathic pain, and altered pain processing.

According to the World Health Organization (WHO), approximately 619 million people worldwide experienced low back pain in 2020, with projections reaching 843 million by 2050. These figures highlight the importance of effective, long-term pain management.

2. Why Traditional Pain Relief May Not Be Enough

2.1 Medication and Physical Rehabilitation

Pain medication can help manage symptoms, but it does not necessarily address every contributing factor. Depending on the medication, prolonged use may also involve risks that require medical supervision.

Physical therapy and exercise can help improve strength, mobility, and activity tolerance. For example, someone with recurring back pain may benefit from strengthening exercises and adjustments to prolonged sitting or repetitive lifting.

The WHO's 2023 guideline for chronic primary low back pain emphasizes individualized care. Depending on the person's needs, treatment may combine exercise, education, and other appropriate interventions.

2.2 The Value of a Multimodal Approach

Long-term recovery often requires more than one strategy. Medical assessment, rehabilitation, activity modification, and appropriate symptom management can address different aspects of pain.

Laser therapy may be considered an additional option for selected conditions, but it should complement rather than replace established treatment. The goal is not simply temporary relief; it is improved function and a better ability to participate in everyday activities.

3. How Does Laser Therapy Work for Pain Relief?

3.1 Understanding Photobiomodulation Therapy

Photobiomodulation therapy uses specific wavelengths of red or near-infrared light to influence biological processes in tissue. Depending on the device, light may be delivered through a laser or light-emitting diodes (LEDs).

Researchers have investigated how light interacts with cellular components, including those involved in mitochondrial function, energy metabolism, and inflammatory signaling. These mechanisms may help explain the interest in PBMT for pain management and rehabilitation.

However, biological changes do not automatically translate into meaningful clinical benefits. Outcomes depend on factors such as the condition being treated, wavelength, delivered energy, treatment duration, and protocol.

3.2 What Does Clinical Research Show?

Laser therapy is an increasingly valuable, non-invasive approach to pain management and rehabilitation, with clinical research highlighting its potential to relieve pain, modulate inflammation, and support functional recovery. Through photobiomodulation therapy (PBMT), specific wavelengths of light interact with biological tissues and may influence cellular activity, inflammatory signaling, and the body's natural healing processes. These mechanisms make laser therapy a promising option for patients seeking alternatives or complementary approaches to conventional pain management.

Clinical research provides evidence of its biological effects. A 2020 randomized, placebo-controlled study involving patients with chronic nonspecific low back pain reported changes in prostaglandin E2 (PGE2), an inflammatory mediator associated with pain, following PBMT. This finding supports the potential of photobiomodulation to influence biological pathways involved in pain and inflammation, reinforcing its scientific rationale as a therapeutic approach.

The clinical value of laser therapy extends beyond its underlying biological mechanisms. In rehabilitation settings, it can be incorporated into individualized treatment plans aimed at reducing pain, improving mobility, and helping patients return to everyday activities. Its non-invasive nature and potential to complement other therapies make it a useful option for clinicians managing musculoskeletal pain and recovery.

Although a 2021 randomized, placebo-controlled trial involving 148 patients did not demonstrate significant superiority over placebo for its primary pain and disability outcomes in chronic nonspecific low back pain, this finding reflects a specific condition and treatment protocol. It does not establish that laser therapy is ineffective across all indications. Treatment outcomes can vary according to diagnosis, wavelength, dosage, treatment frequency, and patient characteristics.

3.3 Laser Therapy vs. LED Red Light Therapy

Laser devices generally deliver more directional light, while LEDs typically emit light over a broader area. Both can be used for photobiomodulation.

Neither technology automatically guarantees better clinical results. Wavelength, irradiance, treatment dose, device design, and condition-specific evidence are all important when evaluating a treatment.

4. Real Patient Cases: What Can We Learn?

4.1 Persistent Shoulder Pain: A Five-Point Reduction in Pain

For patients living with persistent shoulder pain, even simple daily movements can become difficult. A 2020 case report published in the Journal of Back and Musculoskeletal Rehabilitation documented a meaningful improvement in a 31-year-old woman diagnosed with subacromial syndrome whose shoulder pain had persisted despite previous treatments.

The patient received 10 sessions of high-intensity laser therapy (HILT). One month after treatment, her numerical pain rating decreased by five points, while her Shoulder Pain and Disability Index (SPADI) score improved by 24 points. Her pressure pain threshold also increased, providing an additional measurable indication of improvement.

When some symptoms returned three months later, she received five additional treatment sessions. At the subsequent follow-up, six months after these additional sessions, further improvements in pain, shoulder-related disability, and pressure pain threshold were observed.

This case demonstrates the potential of high-intensity laser therapy to deliver meaningful, measurable improvements in persistent shoulder pain. It also highlights the value of reassessing patients over time and adapting treatment plans to their individual recovery needs.

4.2 Postsurgical Scar Pain: From Severe Discomfort to Improved Daily Function

Chronic pain around a surgical scar can persist long after the incision has healed, affecting mobility, sleep, emotional well-being, and quality of life. A 2022 case report published in Scars, Burns & Healing documented substantial improvement in a 32-year-old woman who experienced severe neuropathic pain around an abdominal surgical scar two years after gallbladder surgery.

Before treatment, the patient rated her pain at 10 out of 10. Previous approaches, including topical anesthetic treatment and nerve blocks, had provided limited or short-lived relief. Her pain interfered with movement and daily activities, and she had been unable to return to work.

She subsequently began photobiomodulation therapy (PBMT), using a combination of red and near-infrared light delivered through LED arrays and laser probes. Treatment began in a clinical setting and continued at home according to the prescribed schedule.

The reported improvements were striking. Her pain score fell from 10/10 to 6/10 following the initial treatment period. At the one-year follow-up, she reported a further reduction to 4/10, alongside a visibly flatter scar with less redness. At the latest follow-up described in the report, her pain score had reached 1/10. She had also discontinued several medications under her care team's management, resumed walking and exercise, returned to full-time employment, and regained greater independence.

This case illustrates how photobiomodulation may offer benefits beyond pain-score improvement, with potential gains in mobility, daily functioning, and quality of life. It also demonstrates why laser-based therapy deserves consideration as part of a personalized approach to selected cases of persistent postsurgical scar pain.

4.3 What These Cases Tell Us About Laser Therapy

These two published cases document measurable improvements in different pain conditions: persistent shoulder pain and postsurgical scar-associated neuropathic pain. They show that laser-based therapies can be associated with meaningful changes in pain ratings and, in some cases, improvements in physical function and everyday life.

The clinical takeaway is clear: laser therapy is a promising non-invasive treatment option that merits a place in evidence-informed pain management and rehabilitation. The best treatment approach depends on the patient's diagnosis, the device and treatment parameters used, and an individualized care plan. Larger controlled studies remain important for establishing how consistently these benefits can be reproduced across different patient populations.

5. Building a Long-Term Pain Relief and Recovery Plan

5.1 Choosing an Appropriate Treatment

Treatment should begin with understanding the cause of pain. A protocol studied for shoulder discomfort may not be suitable for neuropathic pain or chronic low back pain.

For laser therapy, relevant factors include diagnosis, wavelength, delivered energy, treatment duration, and safety precautions. Patients should consult qualified healthcare professionals before beginning treatment for persistent or unexplained symptoms.

5.2 Combining Treatment With Lifestyle Changes

For many musculoskeletal conditions, progressive strengthening, mobility exercises, appropriate activity levels, and adequate sleep can support recovery.

Consider someone whose knee pain returns after running. Depending on the diagnosis, a recovery plan might include reviewing training intensity, strengthening surrounding muscles, adjusting recovery periods, and gradually rebuilding exercise tolerance. Laser therapy, if appropriate, may be considered one component of that broader plan.

5.3 Tracking Progress and Recognizing Warning Signs

A symptom diary can help track pain intensity, triggers, sleep quality, medication use, and functional improvements. If symptoms repeatedly return or function deteriorates, reassessment may be more appropriate than simply repeating the same treatment.

New or progressive weakness, significant numbness, fever, or unexplained weight loss warrants medical evaluation. Severe back pain accompanied by new bladder or bowel dysfunction or numbness around the groin requires emergency assessment.

Pain keeps coming back for many reasons, including repetitive physical stress, joint conditions, incomplete rehabilitation, and changes in nervous system sensitivity. Identifying the underlying contributors is essential for effective long-term management.

Laser therapy and photobiomodulation are being investigated for selected pain conditions, but clinical evidence remains mixed. Individual patient cases are informative, yet they cannot establish that a treatment will work for everyone.

The most responsible approach combines accurate diagnosis, evidence-based care, appropriate rehabilitation, and regular assessment. Where supported by condition-specific evidence, laser therapy may be considered an adjunct—not a guaranteed cure or a replacement for medical care.