What does the "O" in the mnemonic OLD CARTS stand for?

The "O" in the mnemonic OLD CARTS stands for "Onset." This terminology is crucial in medical assessments, as it refers to the time when symptoms first began. Understanding the onset helps healthcare providers gather essential information regarding the patient's condition, identify possible causes, and determine the best course of treatment. Knowing when symptoms started can reveal patterns or associations related to the patient's health, enhancing clinical decision-making and improving patient care. By focusing on "Onset," medical professionals can support their diagnostic efforts with important temporal context.