Laser Therapy (Photobiomodulation) for Pain: How Light Helps Tissue Heal

Quick answer: Laser therapy, also called photobiomodulation or low-level laser therapy, shines red or near-infrared light on painful areas to reduce pain and inflammation and support healing. It is painless and does not cut or burn the skin. Good-quality studies show it can reduce pain in neck pain and knee osteoarthritis, but only when the correct dose is used.

What is laser therapy?

Therapeutic laser uses low-power red and near-infrared light. It is completely different from surgical lasers, which cut or burn tissue.

You may hear different names for it: low-level laser therapy (LLLT), cold laser or photobiomodulation (PBM). There is also high-intensity laser therapy (HILT), which uses more power and produces noticeable warmth.

How does laser therapy work?

Think of it like sunlight for plants, but for your cells. The light is absorbed by the mitochondria, the energy factories inside cells. This appears to:

• Boost cell energy production, supporting repair
• Reduce inflammation in the treated tissue
• Calm pain signals from nerves

Dose matters. Too little light does nothing, and too much may switch the effect off. This is why results depend heavily on the device and settings used.

What conditions can laser therapy help treat?

It is commonly used for:

• Neck pain
• Knee osteoarthritis
• Tendon problems, such as tennis elbow, Achilles and shoulder tendinopathy
• Plantar fasciitis (heel pain)
• Low back pain
• Jaw joint pain (temporomandibular disorder)
• Slow-healing wounds

What happens during a laser therapy session?

• You and the therapist wear protective glasses.
• The therapist places the laser probe directly on the skin over specific points.
• Each point is treated for a few seconds to a couple of minutes.
• You usually feel nothing, or mild warmth with high-intensity laser.
• A full session typically takes 5 to 20 minutes. A course is usually 2 to 3 sessions a week for 3 to 6 weeks, alongside exercise.

Who should avoid laser therapy?

Laser should never be shone into the eyes. It should also not be used:

• Over known or suspected cancer
• Over a pregnant abdomen
• Over the thyroid gland in the front of the neck
• Over an area that is actively bleeding

Your therapist should take extra care if you:

• Take medicines that make your skin sensitive to light
• Have tattoos or darker skin in the area, especially with high-intensity laser, as these absorb more heat
• Have reduced skin sensation
• Are a child or teenager with open growth plates in the area

Bottom line: Laser therapy is safe and painless, with reasonable evidence for neck pain and knee osteoarthritis. It works best as part of a programme that includes exercise.

Frequently asked questions

Does laser therapy hurt?

No. Low-level laser is usually not felt at all. High-intensity laser produces a pleasant warmth.

Is laser therapy the same as laser surgery?

No. Therapeutic laser uses low-power light that does not cut, burn or damage tissue.

How long before laser therapy works?

Some people notice less pain after a few sessions. For knee osteoarthritis, studies show the greatest benefit a few weeks after the course ends.

Are home laser devices worth it?

Many home devices are low-powered and may not deliver an effective dose. Ask your clinician before buying one.

Is laser therapy safe for the elderly?

Yes, it is generally very safe for older adults, which makes it a useful option for those who cannot take some pain medicines.

Can laser therapy replace exercise for knee osteoarthritis?

No. Exercise and weight management remain the main treatments. Laser can make exercise more comfortable.