The primary benefit is simply increasing fluid intake, but this may increase nighttime urination and disrupt sleep. In people with reflux or gastric sensitivity, acidity can worsen heartburn. Therefore, lemon water at night is not a universal “good habit.” If you choose to drink it, keep the amount small, do it earlier in the evening, and avoid overly acidic mixtures. In practice, meeting hydration needs during the day is often more effective than late-night strategies.