Your body is made up of 60% water [1] and drinking enough of it is essential to good health. There are numerous benefits of drinking water: improvements in your skin, organ and brain function; flushing out toxins; aiding in digestion and the gastrointestinal (GI) tract; ability to exercise at your best, and overall feeling more energetic and less sluggish.

Most people do not drink enough water. It’s usually a combination of not feeling thirsty until you are slightly dehydrated, not liking the taste of water or forgetting to drink during the day because you’re too busy.

Signs of dehydration

One way to see if you’re not getting enough water is to pinch the skin on the back of your hand; if it doesn’t go right back down, you’re dehydrated. Known as the skin pinch dehydration test, it’s used to see if your skin’s elasticity has been reduced due to a loss of fluid. Other signs of dehydration include:

• Feeling lightheaded or dizzy
• Not urinating enough
• Constipation
• Dry mouth
• Not sweating normally

“Severe dehydration can lead to organ shutdown and death, but fortunately this is rare. Most people are only mildly to moderately dehydrated,” says Lori Vance of Body Fitness Image in Portland, Oregon. Lori is a personal trainer who teaches functional strength and fitness to all age groups.

Causes of dehydration

Hot and humid weather, prolonged exercise, and particularly the two together will require more water intake to allow your body to cool itself through sweating. “Seniors often have a decreased sense of thirst and are at higher risk for dehydration and should be especially careful to drink enough,” Lori notes.

Severe diarrhea and vomiting, diuretics, excessive sweating, and of course not drinking enough water can cause dehydration.

In addition, if you have a headache or feel sluggish, try drinking a big glass of water.

Hydration and hormones

How fluid is controlled in the body is influenced by the brain, and receptors in the blood vessels including those in the heart, neck, and the kidneys. When there is decreased blood flow, the kidneys produce the hormone, renin, which triggers the release of angiotensin constricting blood vessels and triggers the adrenal glands to produce the hormone, aldosterone, and antidiuretic hormone, vasopressin. Aldosterone activates the mineral-corticoid receptors, leading to sodium retention in the kidneys thereby increasing water retention and increasing blood volume. Antidiuretic hormone is produced by the pituitary and causes restriction of blood vessels and causes the kidneys to increase reabsorption of water. As salt levels rise in the blood, the brain is triggered to increase the sense of thirst. Thirst is also triggered by dopamine, habits, taste, and psycho-emotional reasons. [2]

Estrogen and progesterone both influence the hydration status of the body. During the reproductive years for women, the fluctuations of estrogen and progesterone change water management throughout the month. Higher estrogen states as seen prior to ovulation increase water retention. Higher estrogen lowers the thirst triggers in the brain, requiring a lower amount of sodium in the blood to trigger thirst. Estrogen also increases antidiuretic hormone, which increases retention of fluid. Progesterone on the other hand, competes with the hormone, aldosterone, for mineral-corticoid receptors. This has the mitigating effect of decreasing the sodium retention and decreasing water retention.

Premenstrual syndrome - Many women notice significant water weight gain in the five days prior to their period that is relieved with the onset of the period. This is likely due to fluctuations of estrogens and drop in progesterone as well as other hormonal and chemical balances. Supporting progesterone, limiting salt intake, improving liver detoxification of estrogens, and focusing on proper hydration may all help. [3] Interestingly, a year-long study failed to correlate fluid retention to estrogen and progesterone, suggesting that cytokines and prostaglandins may also play a significant role .

Oral contraceptive pills - High levels of ethinyl estradiol and progestins commonly lead to water retention. If this is an issue for you, the progestin, drosperinone, is related to the medication spironolactone, which opposes aldosterone and leads to increased water excretion.

Menopause - The drop of both estrogen and progesterone leads to changes in water management.

Perimenopause - The drop of progesterone leads women to be relatively estrogen dominant and retain more fluid.

Menopause - The drop in estrogen increases water loss and also decreases the sensitivity of the brain to fluid changes. Essentially, this means that thirst is blunted as women age. All of this combines to have dehydration more common in menopausal women. [4]

Hormone replacement - Imbalances in estrogen and progesterone replacement may cause water retention, which can be seen as weight gain and breast enlargement. But, when hormones are well balanced, there is an improvement in water management with improved thirst signaling and water retention. [4]

How much water should you drink?

Lori recommends a starting point of half your body weight (pounds) in ounces of water daily. “A great idea is to always have a water bottle with you so that you can drink all throughout the day,” she advises, “with more emphasis earlier in the day.” Interestingly, minimal research has been done in how much water is necessary to intake for optimal health, but the Dutch scientists found that 2000-3000 mL (8-10 cups) per day does appear to be adequate (Meinders, 2010). This amount compensates for the amount of water lost through sweat, evaporation, urination, and defecation. This amount is also adequate to decrease aldosterone and increase the circulatory volume signaling adequate intake.

Tips for drinking more water

Experiment to find what you like. Chilled water, sparkling water, and water with fruit or berries are great options. Water-rich fruits such as watermelon, grapes, cherries, and berries are also good choices. “Tea without caffeine and with minimal sweetener is also good,” Lori says. Fruit juices can be used if diluted.

Lori recommends drinking from a metal water bottle, which may give a better taste to the water, and therefore, make water more appealing. Here are a few more suggestions:

• Drink a big glass of water when you get up to get your day started on the right track.
• Drink room temperature water versus very cold so that you don’t decrease thirst signals before you're hydrated.
• Limit caffeine and alcoholic drinks unless you are drinking additional water to offset them.
• Sip water throughout the day including during your workout.
• Replace juices and sodas with water. Sugar-sweetened beverages are not good as the health effects and calories counterbalance any benefits.
• Always have a full water bottle with you.
• Avoid drinking large amounts of water close to bedtime as that might disturb your sleep.

Glowing skin is a sign of good health, good nutrition, and good hydration—so, drink up!

References

1. Water Science School. (May 22, 2019). The Water in You: Water and the Human Body. US Geological Survey. Accessed August 5, 2022.
2. Thirst. In: Encyclopedia of Human Nutrition (Second Edition). 2005.
3. White CP, Hitchcock CL, Vigna YM, et al. Fluid retention over the menstrual cycle: 1-year data from the prospective ovulation cohort. Obstet Gynecol Int. 2011;2011:138451.
4. Stachenfeld NS. Hormonal changes during menopause and the influence on fluid regulation. Reprod Sci. 2014; 21(5):555-561.