As a respiratory therapist with extensive experience in oxygen therapy, I can provide insight into the effects of oxygen on the human body. Oxygen is essential for life, but too much of it can indeed be harmful. When a person breathes in oxygen at higher concentrations than what is found in the atmosphere (which is about 21% oxygen), it can lead to oxygen toxicity. This condition can manifest in different ways depending on the body system affected. Central nervous system oxygen toxicity is a concern for deep-sea divers who breathe in oxygen at greater pressures. It can cause symptoms such as seizures, which are characterized by a brief period of rigidity followed by convulsions and potentially unconsciousness. On the other hand, pulmonary oxygen toxicity affects the lungs and can result in damage to the lung tissue. This can lead to symptoms such as pain and difficulty in breathing. Both types of toxicity are generally associated with prolonged exposure to high concentrations of oxygen, and the risk increases with the duration and level of exposure. It's important to note that under normal circumstances, the levels of oxygen we encounter in our daily lives are not high enough to cause toxicity. read more >>

Central nervous system oxygen toxicity can cause seizures, brief periods of rigidity followed by convulsions and unconsciousness, and is of concern to divers who encounter greater than atmospheric pressures. Pulmonary oxygen toxicity results in damage to the lungs, causing pain and difficulty in breathing.read more >>