How Does Low Level Laser Therapy Provide Relief to Painful, Sensitive Areas?
In one sentence: Low Level Laser Therapy numbs the nerve fibres that convey pain, diminishes inflammation, and boosts both the lymphatic and circulatory systems — aiding recovery.
How Laser Therapy Works in Tissue
Laser light reaches the tissue
A wavelength of 670nm, 808nm or 904nm is delivered through the skin via a probe in contact mode.
Mitochondria absorbs the light
Photons enter the cell and are absorbed by a chromophore called cytochrome c oxidase (CCO) in the mitochondrial membrane, increasing its enzymatic activity.
Three signaling molecules respond
Heightened CCO activity affects the production of three key molecules that drive the therapeutic effect:
Adenosine Triphosphate
More cellular energy — boosts the cell's ability to fight infection and accelerates healing.
Reactive Oxygen Species
Modulated signaling activates transcription factors — positively impacting cellular repair.
Nitric Oxide
A potent vasodilator — increases circulation, decreases inflammation, enhances oxygen and immune-cell transport.
A Longstanding Legacy in Medicine
Traditionally, phototherapy has been a staple in medical treatments: blue light for jaundice and staph infections, ultraviolet light for psoriasis, and visible light for seasonal affective disorder.
Low-Level Laser Therapy (LLLT) further extends this legacy by addressing non-healing ulcers, lymphedema, and musculoskeletal pain — presenting a safer alternative to certain drugs like anti-inflammatories and pain relievers.
Photo
= Light
Bio
= Biology
Modulation
= Change
LLLT is also known as Photobiomodulation — changing the biological cells of the body with light.
What a Laser Actually Is
Acronym
Light Amplification by Stimulated Emission of Radiation
A laser is produced by exciting a medium — like a crystal, gas, or diode — with high-intensity electrical stimulation, leading to the generation of photons.
The laser light is released as a coherent wavelength, allowing it to pass through the skin, which in turn imparts its distinct therapeutic properties.
Not All Cold Lasers Are the Same
Cold lasers encompass a range — from visible to invisible types, including infrared and helium-neon variations. Some emit continuous wavelengths, others are pulsed. In physiotherapy, the common wavelengths span 400nm to 970nm.
Each laser variant possesses unique therapeutic attributes influenced by its power, wavelength, and application method. Depending on the wavelength selected, lasers can either stimulate or inhibit tissue responses.
Their therapeutic benefits are vast — from alleviating pain and inflammation to enhancing circulation and lymphatic activity, and expediting the healing of skin and bone injuries.
Treating a Light-Emitting Cell With Light
For laser therapy to work effectively, it must be absorbed by tissues and cells. Our cell's energy producers — the mitochondria — release biophotons: light waves and particles akin to the therapeutic wavelengths of cold lasers.
Mitochondria take in light through chromophores on the cell membrane, making them the principal site for laser absorption. When illness or injury stresses the mitochondria, laser stimulation can boost their performance.
How LLLT Relieves Pain, End-to-End
Four interconnected mechanisms — all triggered by the same beam of therapeutic light.
Laser Pain Relief
Analgesic effect on nerve fibres
Laser provides an analgesic impact on the nerve fibres responsible for conveying pain. It particularly counteracts nerve signals triggered by detrimental stimuli — heat, mechanical stress, or chemical irritants stemming from inflammation — acting right at the nerve's pain receptors.
Clinical research has found that lasers can decelerate nerve conduction anywhere from 10 minutes to a full day, with the effects compounding as cells recover normal function.
Laser treatment on trigger points has been observed to elevate pain-relief-associated neurotransmitters such as serotonin and β-endorphins. These trigger points are hypersensitive spots in muscles, often causing pain at distant sites.
Reduce Inflammation
Lower inflammatory markers
The pain-relieving benefits of LLLT (also known as photobiomodulation) are largely due to its anti-inflammatory properties.
Both animal and human studies using LLLT have demonstrated a decrease in inflammatory indicators like PGE₂ and Substance P — compounds that can heighten sensitivity in peripheral nerves.
Additionally, LLLT promotes the healing process by increasing the presence of neutrophils and macrophages — essential agents for tissue repair. This final step is pivotal for ensuring sustained pain relief.
Decreases
PGE₂ · Substance P
Increases
Neutrophils · Macrophages
Optimising the Lymphatic System
Circulation & swelling reduction
Our lymphatic system operates in tandem with our circulatory system, playing an essential role in healing and reducing the inflammation that can lead to pain and restricted movement.
Obstructions in the lymphatic system — whether from muscle contractions or injury to the fragile lymphatic vessels — can result in pervasive body pain.
Research highlights the effectiveness of the 905nm laser for treating arm lymphedema in breast cancer patients, showing reduced swelling that persists for weeks post-treatment.
The Handy Pulse Laser's primary wavelength. The same frequency shown in studies to reduce lymphoedema swelling.
Releasing Trigger Points
Hyper-reactive nerve endings
Laser therapy can release trigger points — hyper-reactive nerve endings within tense muscle regions — as well as treat nerve entrapments in soft tissues.
Laser devices that combine multiple distinct PBM light wavelengths work well for:
- Treating arthritis
- Promoting wound healing
- Managing inflammatory conditions
- Acute and chronic pain relief