Background: Biophoton emission is the spontaneous emission of ultraweak light emanating from all living systems, including man. The emission is linked to the endogenous production of excited states within the living system. The detection and characterisation of human biophoton emission has led to suggestions that it has potential future applications in medicine. Objectives: An overview is presented of studies on ultraweak photon emission (UPE, biophotons) from the human whole body. Methods: Electronic searches of Medline, PsychLit, PubMed and references lists of relevant review articles and books were used to establish the literature database. Articles were then analysed for their main experimental setup and results. Results: The, mostly, single case studies have resulted in a collection of observations. The collection presents information on the following fields of research: ( 1) influence of biological rhythms, age, and gender on emission, ( 2) the intensity of emission and its left-right symmetry in health and disease, ( 3) emission from the perspective of Traditional Chinese and Korean Medicine, ( 4) emission in different consciousness studies, ( 5) procedures for analysis of the photon signal from hands, ( 6) detection of peroxidative processes in the skin. Of each article the main findings are presented in a qualitative manner, quantitative data are presented where useful, and the technological or methodological limitations are discussed. Conclusion: Photon emission recording techniques have reached a stage that allows resolution of the signal in time and space. The published material is presented and includes aspects like spatial resolution of intensity, its relation to health and disease, the aspect of colour, and methods for analysis of the photon signal. The limited number of studies only allows first conclusions about the implications and significance of biophotons in relation to health and disease, or to mental states, or acupuncture. However, with the present data we consider that further research in the field is justified.
