Why is oxygen therapy sometimes called a "double-edged sword"?

Oxygen therapy is referred to as a "double-edged sword" primarily because it has the potential to both save lives and introduce significant risks, notably oxygen toxicity. While oxygen is critical for sustaining life, especially in patients with respiratory conditions, excessive oxygen levels can lead to harmful effects. Oxygen toxicity can result in damage to lung tissues, cause seizures, and lead to other complications, particularly when high concentrations are administered over prolonged durations.

This duality—where proper use of oxygen therapy can greatly benefit patients with conditions like chronic obstructive pulmonary disease (COPD) or during respiratory distress, while misuse or over-administration can lead to serious health issues—highlights the complex nature of its application in medical treatment. Balancing the life-saving aspects with the associated risks is essential in clinical practice, thus underscoring the "double-edged" characterization of oxygen therapy.