Do you drink enough water every day?

Hydration experts warn many adults fall short of recommended daily fluid intake, a gap linked to cognitive and physical symptoms, new analysis finds.

A review by the National Hydration Council and independent researchers examined surveys and clinical studies assessing self-reported fluid consumption and biomarkers of hydration. The analysis notes that commonly cited guidance — about eight 8-ounce cups, or 64 fl oz (1.9 L), of fluid daily — may underestimate needs for many adults. Instead, scientists reference the National Academies' adequate intake: roughly 125 fl oz (3.7 L) for men and 91 fl oz (2.7 L) for women, said lead author Dr. Elena Ramirez, a nutrition epidemiologist.

"Total water needs vary with activity, climate and health status," Ramirez said. "Relying only on a universal cup count can leave people underhydrated, particularly older adults and athletes."

Clinical evidence links chronic low fluid intake to increased kidney stone risk, urinary tract infections and impaired concentration. Registered dietitian Mark Chen, who runs a community hydration program, said practical strategies include carrying a reusable bottle, setting hourly reminders and consuming water-rich foods. He advised starting with 16 fl oz (0.47 L) upon waking and adjusting intake around exercise.

The analysis emphasizes objective measures such as urine concentration and bodyweight changes during exertion to tailor recommendations. Public health officials call for clearer guidance that accounts for temperature, activity and individual conditions, noting that thirst may be an unreliable sole indicator, especially in older adults.

Future research will refine personalized hydration thresholds. Meanwhile, the review encourages clinicians and employers to promote accessible water sources and educational campaigns so individuals can better answer whether they drink enough water every day. Experts urged routine monitoring and consultation with clinicians to set safe, individualized targets based on medical history, medication use and environmental demands for optimal daily hydration outcomes.