The rise in body temperature:
Sweat is how your body typically cools itself and maintains its internal temperature. Without enough water, your body cannot properly sweat and as a result, your core temperature increases, which can make you feel hot.
Drop-in blood pressure:
Minagawa says dehydration occurs largely because of a decrease in the volume of plasma—which is the liquid part of the blood that contains proteins—and as a result, blood pressure also drops.
Nausea or vomiting:
In response to the rise in internal body temperature, a drop in blood pressure, and an increase in heart rate, you could become nauseous or even start throwing up.
Muscle cramp:
Sweating may cause a decrease in both plasma volume and electrolyte levels, which is associated with exercise-induced muscle cramps.
Constipation:
Water helps to move food along through your gastrointestinal system. A water deficit could cause you to feel backed up. Inadequate fluid consumption is touted as a common culprit in constipation and increasing fluid intake is a frequently recommended treatment. Sluggish bowel function is a result of the water receptors in the colon not getting enough water to soften the stools.
Higher Risk of Stroke
Not drinking enough water and being dehydrated can increase the risk of strokes and prolong recovery time, if you’ve had one.
Skin Problems
Excessively dry skin and chapped lips are all signs of dehydration. When you have too little water available in your body you also sweat less. This leads to clogged pores, cysts, and acne breakouts.
Joint Pain
Your joints and spinal disks are made up of about 80 per cent water. Staying hydrated keeps them working well so they can absorb the shock of jumping, running, or falling. Lack of water in the body can cause the bones to rub against each other, creating chronic joint pain.
Dizziness and Headaches
When you’re not hydrated, you live with a lower-than-normal blood volume. This can lead to low blood pressure which causes dizziness, vertigo and nausea. The lack of oxygen in your blood can also be the reason you experience frequent headaches. Since your brain needs water when it’s lacking it can lead to headaches and fatigue. It is recommended that water deprivation-induced headache is the result of intracranial dehydration and total plasma volume.
Lethargy and Fatigue
When you’re dehydrated, your blood thickens. This means your heart has to work harder to circulate your blood, making it more difficult to spread the oxygen and nutrients your body needs. If you’re constantly feeling fatigued, your body could be trying to tell you that you’re not drinking enough water.
Digestion Issues
The stomach and digestive system are lined with mucus membranes that require water to function properly. If you’re suffering from stomach pain, heartburn, indigestion, ulcers, constipation, or bloating, a glass of water might be just what the doctor ordered.
Decreased Urination
When you’re hydrated, you should expect to make at least four to seven trips to the powder room every day. This may seem inconvenient, but it’s an indicator of good health. It’s also far better than suffering from urinary tract infections that are usually caused by dehydration.
Irritability
If you’ve ever felt “hangry,” you know how lack of food can impact your mood. Likewise, dehydration can lead to mood swings, irritability, depression, anxiety, and hormone imbalances.
Difficulty with Weight Management
Dehydration can obstruct liver function, which may lead to cravings for sweet or salty snacks. Match this with the fact that people often mistake the sensation of thirst for hunger, and it’s not surprising that not drinking enough water can slow your ability to lose weight. As shown in a small study from The Journal of Clinical Endocrinology and Metabolism, 17 ounces of water (around two glasses) can increase the metabolism by 30%, which is important when you're looking to lose weight.
Overeating
Sometimes we confuse thirst with hunger, so it’s smart to drink water when you feel a craving coming on instead of digging right into the cookie jar. That’s why it’s a good idea to drink water before sitting down to a meal, as you may consume fewer calories and you’ll have a better sense of your hunger cues and appetite.
Premature Aging
Water is crucial for skin elasticity. Deny your body the fluids it needs, and it will retaliate in the form of fine lines and wrinkles, undereye bags, loose and sagging skin, and crow’s feet. Proper hydration is the key to maintaining a healthy glow.
Poor Skin
The skin contains approximately 30% water, which contributes to plumpness, elasticity, and resiliency. Skin needs to stay hydrated from water to look dewy and young. Not drinking enough can increase the effects of ageing and make skin look drier, flakier, wrinklier. With insufficient water, collagen can crack, leading to fine lines and wrinkles. That's why people need moisturizing, hydrating products in a skin-care regimen to complement their water intake for that supple, soft look.
Weight Gain
While a little gain isn't dangerous, if it continues over time or is in the belly region, in particular, that gain can put you at risk for various chronic diseases, such as diabetes, heart disease and more. Drinking water can even help you lose weight and decrease water retention. And likely you'll consume fewer calories from filling up on good old liquid and preventing confusion between hunger and thirst cues.
Dry mouth
If you’re not getting enough water, you can have dry mucous membranes—i.e., a lack of saliva. This can make it difficult to talk, swallow, and even breathe.
Weaker Workouts
When you're sweating, you're losing electrolytes and water, so it's essential to drink before, during and after working out to replenish lost stores. Workouts suffer from a lack of water, and your body may not burn as much fat.
References:
1. Nicolaidis S. Physiology of thirst. In: Arnaud MJ, editor. Hydration Throughout Life. Montrouge: John Libbey Eurotext; 1998. p. 247.
2. Jequier E, Constant F. Water as an essential nutrient: the physiological basis of hydration. Eur J Clin Nutr. 2010;64:115–123.
3. Food and Nutrition Board Institute of Medicine of the National Academies. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. The National Academies Press; Washington DC, USA: 2005. pp. 73–185.
4. EFSA. Scientific Opinion on Dietary Reference Values for water. [(accessed on 1 October 2010)];EFSA J. 2010 8:1459. Available online: http://www.efsa.europa.eu/en/scdocs/scdoc/1459.htm.
5. Hsieh FI, Lien LM, Chen ST, Bai CH, Sun MC, Tseng HP, et al. Get with the guidelines-stroke performance indicators: surveillance of stroke care in the Taiwan stroke registry: get with the guidelines-stroke in Taiwan. Circulation. 2010;122(11):1116–1123. doi: 10.1161/CIRCULATIONAHA.110.936526.
