phototherapy

American  

[foh-tuh-ther-uh-pee] / ˌfoʊ təˈθɛr ə pi /

noun

1. treatment of disease, especially of the skin, by means of light rays.

2. light therapy.

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phototherapy British  

/ ˌfəʊtəʊˈθɛrəpɪ, ˌfəʊtəʊˌθɛrəˈpjuːtɪks /

noun

1. (functioning as singular) the use of light in the treatment of disease

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Other Word Forms

• phototherapeutic adjective
• phototherapeutically adverb
• phototherapic adjective
• phototherapist noun

Etymology

Origin of phototherapy

First recorded in 1895–1900; photo- + therapy

Example Sentences

A special home phototherapy device to treat psoriasis is as effective as going to a doctor’s office for the therapy, according to research funded by the Patient-Centered Outcomes Research Institute.

From The Wall Street Journal • Sep. 30, 2025

He further remarked, "It would be also used for wearable photonic biosensors and phototherapy systems in extreme environments."

From Science Daily • Mar. 6, 2024

The most commonly used ones - phototherapy, tacrolimus and topical corticosteroids - can all have their downsides.

From BBC • Mar. 6, 2023

If self-care doesn’t help, see a doctor, who might prescribe a biologic drug for inflammation, methotrexate to slow skin-cell growth, or phototherapy.

From Washington Post • Dec. 30, 2016

Newborns with hyperbilirubinemia are treated with phototherapy because UV light helps to break down the bilirubin quickly.

From Textbooks • Jun. 19, 2013