Dehydration: Overview

Thirst can be a poor way of monitoring of your water needs.  You can lose your thirst sensation and the critical perception of needing water.  No longer recognizing a water need (unless very dehydrated), you can become gradually, increasingly, and chronically dehydrated with increasing age.  A "dry mouth" may be a late sign of dehydration.

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Water has many functions in your body.  Water:

  • Transports vitamins, minerals, amino acids, glucose, hormones, enzymes and other substances throughout your body
  • Assists chemical reactions such as the burning of glucose and the breakdown of fat for energy
  • Carries digestive juices
  • Lubricates joints, eyeballs, nasal passages, and the intestines
  • Is a shock absorber for your eyes and spinal cord
  • Maintains your body temperature – cools it by evaporation from the skin and lungs, throws off heat when blood is circulated near the body's surface – helps retain warmth in winter
  • Removes wastes through the kidneys and helps solid waste pass through the intestines
Two urine samples, light yellow on left and brown on right
Urine color should be light yellow (left); darker urine (right) usually indicates dehydration, but may indicate disease.

Here are some interesting facts:

  • 75% of Americans are chronically dehydrated.  (This likely applies to half the world population)
  • Even MILD dehydration will slow down one's metabolism as much as 3%.
  • One glass of water shut down midnight hunger pangs for almost 100% of the dieters studied in a University of Washington study.
  • Lack of water is the #1 trigger of daytime fatigue.
  • Preliminary research indicates that 8-10 glasses of water a day (half of that coming from food and drinks other than plain water) could significantly ease back and joint pain for up to 80% of sufferers.
  • A mere 2% drop in body water can trigger fuzzy short-term memory, trouble with basic math, and difficulty focusing on the computer screen or on a printed page.
  • Drinking 5 glasses of water daily decreases the risk of colon cancer by 45%, the risk of breast cancer by 79%, and one is 50% less likely to develop bladder cancer.  Are you drinking the amount of water you should every day?

Signs and Symptoms

Pain may be a warning of localized thirst; that is, the pain signal may be a warning of dehydration in that specific area (a regional thirst), for example low back pain, migraine headache, joint pain, and angina.  Chronic dehydration may contribute to a reduction in lymph flow, which in turn may contribute to or cause varied problems.

Obvious signs of dehydration include: crinkled skin, dry mouth, excess thirst or absence of urination for over six hours.

Treatment and Prevention

It is a common error to substitute tea, coffee, caffeine-containing soft drinks, or alcohol-containing beverages for water.  Do not consider alcoholic beverage, soda, coffee or tea as an equal substitute for water.  Caffeine and alcohol act as diuretics, further increasing your water needs.

Close-up slow motion capture of water pouring
Sufficient daily water intake is essential for good health. Recommended amount depends on environment, body build and activity.

Remember that approximately half of your daily water intake comes from the food that you eat, so you only need to drink around half of your suggested requirement directly.

Calculate your overall daily need by taking your weight in kilograms (or your weight in pounds divided by 2), in ounces per day.  For example, 140lbs / 2 = 70oz; 70oz / 8 = about 9 cups per day.

It is recommended by some that you not drink water with meals, unless you need to.  Other doctors believe that the stomach needs a certain consistency to do its job and if we don't drink enough with our meals the stomach pulls water from the blood stream; if we drink too much with our meals the excess water simply gets absorbed.  The logical recommendation, therefore, is to try both and see what works best for you.

Good times to drink water are on rising, at least 12 hour before meals and 2-3 hours after, and before bed.  You need more if the temperature is hot and if you exercise.  A general rule is to add an extra 2 glasses per day for every 5°F over 85°F if you are at rest, and more if you exercise.

References and Further Information

We recommend that you read Your Body's Many Cries for Water by Dr. Batmanghelidj, MD.  It may be available from your local library.  If purchased, you may be able to help others you think of while reading it!

"In my professional and scientific view, it is dehydration that is the biggest killer, more than any other condition you could imagine.  The different aspects and 'chemical idiosyncrasies' of each individual's body reaction to the same pattern of dehydration have received different professional labels and have been treated differently and ineffectively." Dr. Batmanghelidj, MD.

Signs, symptoms & indicators of Dehydration:

Lab Values - Common

Symptoms - Aging

(Greatly) reduced skin elasticity

Inelastic skin is a sign of severe chronic dehydration.

Symptoms - Allergy

Symptoms - Food - Beverages

Symptoms - Food - General

Symptoms - Gas-Int - General

Symptoms - General

Symptoms - Head - Eyes/Ocular

Symptoms - Head - Mouth/Oral

Symptoms - Head - Nose

Symptoms - Metabolic

Adverse reaction to delayed meals

When we skip meals, we often also skip the drinks that go with the food.  If your hydration status is already marginal, a delayed meal may be enough to trigger dehydration symptoms.

Symptoms - Mind - Emotional

Symptoms - Mind - General

Symptoms - Nails

Symptoms - Nervous

Symptoms - Reproductive - General

Symptoms - Skeletal

Symptoms - Sleep

Symptoms - Urinary

(Very) cloudy urine

Yellow and/or cloudy urine may be evidence of a water intake deficiency.

Conditions that suggest Dehydration:





Dr. Bantmanghelidj, MD in his book Your Body's Many Cries for Water reports many cases of angina attacks being reduced by drinking adequate water.

Dental / Oral


Heartburn / GERD / Acid Reflux

Dr. Batmanghelidj, author of Your Bodies Many Cries for Water, believes that in the same way we have a "hunger pain" signal, we also have a "thirst pain" signal in the body, and that it is called dyspepsia (heartburn).


Lymphatic Congestion

Drinking plenty of water makes sure the body is well-hydrated and helps the lymphatic system do its job of flushing toxins and waste from the body.

Lab Values




Susceptibility To Hangovers

The most obvious source of headaches due to hangovers is dehydration caused when alcohol suppresses anti-diuretic hormone.  This hormone normally orders the body to conserve water, but alcohol dulls the command, causing people to lose far more water to urination than they take in with the alcohol.

The body reacts to the open floodgates by borrowing water from other organs, such as the brain.  As a result, the brain shrinks.  While that may not cause pain by itself, the brain has a covering called the dura that is connected to the skull by pain-sensitive filaments.  Deformation of the dura can cause the headaches that come with a hangover.


Gout / Hyperuricemia

Gout can be caused by dehydration and the use of diuretics such as coffee or alcohol.

Muscle Cramps / Twitching

Excess sweating or dehydration can deplete minerals in the body – minerals that are important for good muscle function, such as sodium, potassium, calcium, magnesium and phosphorus.

General Weakness

A loss of 4-5% of body weight of fluid decreases the capacity for hard muscular work by 20-30%.

Neck / Spine

Nervous System

Organ Health

Kidney Disease

Renal insufficiency can occur from underperfusion due to dehydration.




Leg Cramps At Night

Dehydration may play a role in muscle cramping.

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Risk factors for Dehydration:


Caffeine Intoxication

Dehydration may result from the increased urinary frequency brought on by caffeine.

Excess Protein Consumption

High protein intakes may lead to dehydration due to excessive urine output (related to ketone production).



Diarrhea can rapidly drain your body of water, causing dehydration.

Ulcerative Colitis

Dehydration occurs in patients with severe diarrhea as seen in ulcerative colitis.


Symptoms - Allergy

Symptoms - Food - Beverages

(High) coffee consumption

Caffeine has a mild diuretic action and may thus worsen dehydration, except when taken during exercise.  One study found that the difference between ingesting the same volume of a non-caffeinated sports drink and the same drink containing caffeine (25mg per 100ml) was that urine production after the caffeinated drink was significantly higher at rest by 31%.  However, ingestion of caffeinated beverages during physical activity did not increase urine production and exacerbate dehydration. [International Journal of Sports Medicine. 18: pp.4046-4053, 1997]


Symptoms - Gas-Int - General

Symptoms - Mind - Emotional

Symptoms - Skeletal

Dehydration could instead be:


Alzheimer's Disease

Due to older people's precarious homeostatic mechanisms they are much more prone than younger people to dehydration and electrolyte imbalances.  This may induce a confusional state which may be mistaken for a dementing illness such as Alzheimer's.

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