PQRS is a mnemonic used in pain assessment to help healthcare professionals gather comprehensive information about a patient's pain. Each letter stands for a different aspect of the pain experience: P (Provokes/Palliates), what makes the pain better or worse; Q (Quality), how the pain feels (e.g., sharp, dull, burning); R (Region/Radiation), where the pain is located and if it spreads; S (Severity), the intensity of the pain on a scale (e.g., 0-10); and T (Timing), when the pain started and how often it occurs. Using PQRS ensures a thorough understanding of the patient's pain, leading to more effective treatment.