What would happen if you breathe pure oxygen?

Breathing pure oxygen, especially at high concentrations, can be dangerous and lead to a condition known as oxygen toxicity. Oxygen toxicity can cause a variety of symptoms and health issues, including: 1. Central Nervous System (CNS) Effects: At elevated levels, oxygen can have a sedating effect, but paradoxically, it can also lead to symptoms such as irritability, confusion, and tremors. Prolonged exposure can result in more severe neurological problems. 2. Pulmonary Oxygen Toxicity: Breathing high concentrations of oxygen can damage the lungs, leading to a condition called adult respiratory distress syndrome (ARDS), which can be life-threatening. 3. Ocular (Eye) Effects: Oxygen toxicity can also affect the eyes, potentially causing a condition known as retinal toxicity, which can lead to vision problems. 4. Seizures: One of the most serious effects of oxygen toxicity is the potential for seizures, which can be fatal if not treated promptly. 5. Other Effects: Long-term exposure to high concentrations of oxygen can also lead to other issues such as oxygen-induced barotrauma and the formation of oxygen free radicals, which can damage cells and tissues throughout the body. It's important to note that the risk of oxygen toxicity depends on the concentration of oxygen and the duration of exposure. Medical oxygen therapy is carefully monitored to prevent these issues, and pure oxygen is typically only used for short periods in medical emergencies.

If you breathe air with a much higher than normal O2 concentration, the oxygen in the lungs overwhelms the blood's ability to carry it away. The result is that free oxygen binds to the surface proteins of the lungs, interferes with the operation of the central nervous system and also attacks the retina.