What is light therapy (phototherapy)?
Light therapy, or phototherapy (light therapy) is a method in which the body is exposed to light waves of a certain spectrum in order to produce a therapeutic or health-promoting effect. This can be natural sunlight or specially designed light devices. It is a scientifically based treatment method in which light of a certain wavelength is used to regulate the functions of the human body and improve health. Simply put, it is a controlled exposure to light on the skin or eyes, which can have a positive effect on mood, skin condition, sleep and even immunity.
This therapy is not new – it has long been used in medicine: neonatology (neonatal jaundice), dermatology (psoriasis, vitiligo, eczema) and psychiatry (mood disorders, especially seasonal depression). Today it is also gaining popularity in aesthetic and regenerative medicine (Elmets et al., 2019; Cleveland Clinic). Light therapy is becoming increasingly relevant In Lithuania, where the long dark season, lack of sunlight, and the increasing prevalence of skin and psychological disorders encourage the search for non-invasive, safe, and effective solutions.
In this article, we will clearly explain, What is light therapy, how does it work and what are its basic principles?.
About light therapy (phototherapy)
Light therapy (phototherapy) is a treatment method that uses artificial or natural light to influence biological processes in the body. During phototherapy, light energy is converted into a biological signal that stimulates cell activity, hormone release, or the reduction of inflammatory processes. This principle is widely used in dermatology (treatment of psoriasis, acne), correction of sleep disorders, and mental health (National Institutes of Health (NIH)).
Key facts about light therapy:
- Specific wavelengths of light are used (blue, red, infrared);
- The therapy works through the skin or eyes;
- The method is recognized in medicine and supported by clinical research.
How does light therapy work?
Different light waves can affect our bodies in very different ways.
- Mitochondrial activation – red and infrared light stimulates mitochondria, increasing ATP production, which accelerates healing and tissue regeneration (Hamblin, 2016).
- Regulation of circadian rhythms – bright white or blue light helps normalize the sleep-wake cycle (American Psychiatric Association, 2021).
- Correction of skin processes – ultraviolet light (UVB) is used to treat psoriasis, vitiligo or dermatitis (Elmets et al., 2019).
These processes explain why different types of light are used to solve different problems.
What are the types of light therapy?
|
Type of therapy |
Waves used |
Main purpose |
Scientific justification |
|---|---|---|---|
|
UVB phototherapy |
UVB ~311 nm |
Dermatology: psoriasis, vitiligo, eczema |
Efficacy proven in clinical guidelines (Elmets et al., 2019) |
|
Blue light therapy |
400–500 nm |
Acne treatment, antibacterial effect |
Reduces C. acnes bacterial activity (Javed, Huh, 2024) |
|
Red and infrared light therapy (photobiomodulation) |
600–900 nm |
Reducing inflammation, promoting healing, slowing skin aging, controlling pain |
Mitochondrial activation, collagen synthesis (Hamblin, 2016; Wunsch, Matuschka, 2014) |
|
White bright light |
Broad spectrum (especially blue) |
Treatment of seasonal depression and sleep disorders |
Regulates the production of melatonin and serotonin (Cleveland Clinic; American Psychiatric Association, 2021) |
UVB phototherapy
UVB phototherapy – is the use of ultraviolet B spectrum light to treat skin diseases.
It is most commonly used in dermatology to treat psoriasis, vitiligo, or atopic dermatitis. This light affects the skin's immune system and helps reduce inflammation and excess cells. The therapy is performed under controlled conditions, usually in medical facilities.
Blue light therapy
Blue light therapy is used to treat acne and control bacteria.
This light affects bacteria Cutibacterium acnes, which cause acne, and helps reduce skin inflammation. It is often used in cosmetology and dermatology as a non-invasive treatment method. The therapy can be applied both in clinics and at home with special devices.
Red and infrared light therapy (photobiomodulation)
Red light therapy Designed for tissue regeneration, pain relief and skin condition improvement.
Red and infrared light penetrate deeper into tissues and affect mitochondria, the energy-producing centers of cells. This stimulates ATP production, collagen synthesis, and reduces inflammation.
Bright white light therapy
Bright white light therapy
White light therapy commonly used for seasonal affective disorder (SAD) and insomnia. Bright light acts through the eyes and helps regulate the production of melatonin and serotonin, which are important for sleep and emotional state.
Benefits for the body
- For skin diseases – reduces symptoms of psoriasis, vitiligo, acne (Elmets et al., 2019; Javed, Huh, 2024).
- For pain and inflammation – photobiomodulation reduces inflammation, helps recover after injuries or intense training (Hamblin, 2016).
- For sleep and mood – bright light helps treat seasonal depression and insomnia (Cleveland Clinic).
- For aesthetic medicine – red light therapy can reduce wrinkles and improve skin elasticity (Wunsch, Matuschka, 2014).
Benefits of light therapy
Light therapy can have a wide range of effects on the body. Key benefits include:
- Helps treat skin diseases (psoriasis, acne, vitiligo)
- Reduces pain and inflammation
- Improves sleep quality
- Helps stabilize mood
- Promotes skin renewal and collagen production
It is important to understand that the effect depends on the type of light chosen and the individual reaction of the body.
How to use light therapy safely?
Light therapy can be safe if used properly and according to recommendations.
Medical procedures such as UV phototherapy should be performed under the supervision of a professional. Improper use can cause skin or eye irritation. Caution is also required for people with photosensitivity or those taking certain medications.
- Excess UV rays can increase the risk of skin cancer, so therapy should only be applied under the supervision of a specialist (Elmets et al., 2019).
- Improper use may cause skin redness, eye irritation or headaches (Cleveland Clinic).
- It is important to follow the manufacturer's instructions, as too high a dose may reduce the benefits of therapy or even cause harm (Hamblin, 2016).
Conclusions
Light therapy is a broad, scientifically based field of treatment and health support that encompasses several different technologies and application methods. Each type of light has its own specific effects on the body, so it is important to choose the right method based on your needs.
- Light therapy works through the body's biological processes
- Different waves perform different functions
- It is widely used in medicine and aesthetics.
- Can help both physical and psychological health
- Safety depends on proper use
To summarize it in one sentence: light therapy is the controlled use of different light waves to affect body functions and improve health.
Read more about light therapy: https://stokas.lt/raudonosios-sviesos-terapija/