Introduction In current medicine there is an unlimited portfolio of diagnostics tools and therapeutic modalities to treat various conditions. The utilisation of CO2 gas has a long tradition in many branches of medicine, be it in form of systemic (inhalation) or local (transdermal, intradermal, subdermal, and intramuscular) therapy. The term “carboxytherapy” today denotes predominantly the utilisation of CO2 gas in injection form. Carboxytherapy – therapeutically applied carbon dioxide injections have been used in balneotherapy since 1932, thanks to the balneotherapists from the French Royat Spa. Since then, the number of publications dealing with carboxytherapy has been increasing every year, advocating the great effects of this therapeutic modality. In balneotherapy, the said “gas injections“ are applied predominantly to treat joint problems and impaired blood circulation in the lower extremities (ischemic disease) and in the skin of diabetic patients, but also in some patients with systemic vascular diseases and diseases of the heart (bradycardia, low blood pressure) [1,2,8,12,15,17,18,20,23,24]. In the last two years, however, this treatment modality has become the centre of attention as a unique method applicab example of respiration of all aerobic organisms and fermentation, combustion of wood, carbohydrates and fossil fuels such as coal, peat, petroleum and natural gas. Under normal pressure it occurs in form of gas, while its instable solid form is referred to as dry ice. Carbon dioxide is a common compound of atmosphere, whereby its concentration (CO2 gas measurements) in atmosphere oscillates depending on local conditions, altitude, and relative air humidity. Due to especially industrial emissions, its average concentration in the air keeps growing [8,10,19]. CO2 and its transport in bodily tissues Physiologically, the human body produces approximately 1.0 kg of CO2 a day, which contains 290 g of carbon. CO2 is transported by the venous system (high content CO2 ) and exhaled by the lungs (low content CO2 ). The arterial system shows only a low concentration. The content of CO2 in bl