Medical oxygen has become one of the most important life-saving commodities in the fight against COVID-19 during which patients develop pneumonia and hypoxaemia – a low blood oxygen level. Dozens of COVID-19 patients in India have died due to the acute shortage of oxygen, bringing the production and supply of this critical medical item into the global spotlight. When is medical oxygen used? How is it administered? Which countries produce the most of it? And how is it produced? We answer these questions in four graphics. The impact of COVID-19 on the lungs The Sars CoV-2 virus in many cases targets the respiratory system, leading to an inflammation of the lungs. In severe cases, this may lead to hypoxaemia, which is the leading cause of death among COVID-19 patients.