Almost everything in the body is both amazingly and annoyingly connected , including the pathways that regulate water balance and cortisol release.

A recent study (Daniel S. Kashi et al., 2025) confirmed that hydration status can influence how the body releases cortisol in response to psychosocial stress. This matters because cortisol reactivity to stress is a strong predictor of long-term health…and right now, about 75% of Americans are under-hydrated. Considering the stress load of 2025, that’s not great news.

If staying hydrated can help us respond to stress more favorably, then maybe the joke about having an “emotional support water bottle” carries some real truth.

Cortisol 101

Cortisol is a hormone central to the body’s stress response. It boosts survival mechanisms by increasing glucose for energy, enhancing alertness, and sharpening focus, while temporarily suppressing nonessential functions like reproduction and digestion.

Cortisol can surge within minutes of a stressful event but may take one to two hours to break down. When cortisol responses are exaggerated or prolonged, it can disrupt metabolism, immunity, and inflammation.

Ideally, cortisol levels rise naturally upon waking and taper off throughout the day. However, cortisol isn’t just triggered by emotional stress…it can also be released when basic needs like hydration aren’t met. Frequent, high-level cortisol activation can eventually lead to dysregulation, leaving people chronically “stuck” with cortisol levels that are too high or too low.

Hydration Matters

Suboptimal hydration is linked to higher risks of kidney, cardiovascular, and metabolic diseases. With chronic disease rates already high in America, it’s not surprising that 75% of adults are not drinking enough fluids.

A general daily target is around 90 ounces for women and 120 ounces for men, or roughly half your body weight in ounces. Individual needs can vary depending on activity level, climate, and overall health.

A simple hydration check? Look at your urine color. Pale yellow is ideal. Bright, golden, or dark yellow signals it’s time to drink more fluids.

While water should be your main source, other beverages like coffee, tea, milk, and juice, along with water-rich foods, also contribute to total intake. Staying well hydrated supports healthy cortisol reactivity, allowing cortisol to clear efficiently so it can follow its natural rise-and-fall rhythm.

Hydration won’t make stress disappear, but it helps the body handle it better and that’s a simple, powerful step toward resilience.

TakeawaysStaying hydrated may help your body regulate its stress response and improve long-term health.Aim to drink half your body weight in ounces daily (about 90 oz for women, 120 oz for men).Start your day with a big glass of water, add electrolytes if your lifestyle or environment calls for it.Keep your literal emotional support water bottle nearby throughout the day.Hydrate before, during, and after exercise.Pay attention to cues like thirst, fatigue, dark urine, or headaches, your body’s subtle reminders to drink up.

Cheers to being happily hydrated and to getting a few extra steps in with every trip to refill that water bottle.

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