Think about a grape versus a raisin. The one is plump and full and juicy containing all its natural water. The other is small, dry, shriveled, its water gone. Although a dehydrated grape (raisin) is good and useful fruit, when our human body is dehydrated, it does not function at its best and may be at risk for many ailments.

The body is composed of nearly 75% water and water is required to be solvent, transport nutrients, hormones and other elements. It is used to produce hydroelectric energy especially in the brain. It maintains cell structure and lowers serum thickness enabling proteins and enzymes to function more efficiently.

Think about it, as fetuses, we were surrounded by water until the time of birth when the waters broke!

Chronic dehydration can lead to decrease in these functions causing disease or exacerbating existing conditions. By the time you get dry mouth or thirsty, you are already dehydrated!

And if you are dehydrated, you cannot really expect to be healthy. Since the body is mostly water, it just doesn’t function properly without adequate water.

How Awesome the Body Is!

When the body is water-deprived, histamine, a neurotransmitter becomes active and redistributes water through the body in this order: brain, lungs, liver, kidneys, glands, muscles, bones, and skin.  When the supply of water isn’t replenished, histamine takes it from the cells. This can result in common conditions like, colitis, constipation, dyspepsia, rheumatic arthritis, chronic pains, migraine headaches, and asthma.

Early signs of dehydration:

Dry Mouth

Dry mouth is actually your body’s last outward sign of extreme dehydration. When our bodies are being deprived of water, our thirst mechanism becomes disabled. So, by the time you realize your mouth is dry and you should have a drink, you are already extremely dehydrated.

Chronic dehydration can lead to a decrease in these functions causing disease or exacerbating existing conditions.


Heart burn, dyspepsia

Your digestive process involves hydrochloric acid and pancreatic bicarbonate, which require large amounts of water to work properly. If enough water is not available, the process is delayed in the stomach and acid rises, producing heartburn.  Ideally, you should drink water 30 minutes before meals, during meals and 2 hours after eating to keep from developing heartburn due to dehydration.


Joint pain

The cartilage in the body, including in the joints is composed mainly of water. When dry cartilage surfaces glide over one another, it will feel like Melba toast rubbing together! If there is inadequate water to transport nutrients to the cartilage, your body is unable to replace the old worn cartilage cells. This leads to painful joints as the cartilage is damaged.



When water is in short supply the colon will restrict unnecessary water loss through the stools and just save it up. The colon muscles contract to squeeze out water and reabsorb it into circulation. This process may cause pockets/diverticuli that can lead to other health issues.


Asthma and allergies 

When you are dehydrated this causes a production in the neurotransmitter histamine which is the sensor regulator of water metabolism and its distribution in the body.


Elevated histamine will promote the thirst response.


Apart from its obvious water role, histamine has responsibilities your body’s defense system. So when your body’s water level is normal, then histamine levels are in check. But as soon as you are just slightly dehydrated, the histamine level rises thus causing allergy and asthma symptoms.

In animal studies it has been shown that histamine will decrease with water intake and increase with dehydration. According to Dr. Batmanghelidj, author of “You Are Not Sick You’re Thirsty”, increasing your water intake can help alleviate allergies and asthma within one to four weeks!

Additionally, we need water to breathe. In fact, our lungs must be moist to take in oxygen and expel carbon dioxide. Therefore, if dehydrated blood reaches the lungs, histamine will be produced and this promotes bronchial constriction. Since your lungs use up to 1 pint of water a day, it stands to reason that bronchial constriction will occur to preserve water. Think of the implications this has for children who suffer from asthma.



Dehydration affects Serotonin production. While there are a number of reasons for depression, one of the most significant reasons is insufficient levels of serotonin, a very important neurotransmitter.

Serotonin is made from the amino acid tryptophan in the brain. When dehydration exists, transport of tryptophan is deterred and it goes to the liver to help the body get rid of toxins created by the dehydrated state. Since Serotonin goes on to make Melatonin, (aids in sleep) sleep problems will most likely occur due to low melatonin levels..


High blood pressure

Dehydration actually decreases blood volume. When the blood volume decreases, the body closes down capillary beds in order to keep the larger vessels full. This causes a resistance to blood flow that then requires blood pressure to rise (hypertension) to ensure passage of blood through the system.


Migraine Headaches

Researchers claim drinking water could be a simple cure for migraines. Drinking between 6 and 8 glasses a day can reduce migraine intensity and duration according to the European Journal of Neurology.  Although there are other factors at play in the trigger of migraines, studies have revealed dehydration is a definite contributor to attacks.

According to Dr. F. Batmanghelidj, other psychological disorders associated with dehydration include feeling:

  • Tired without a plausible reason
  • Flushed
  • Irritable and unreasonably short tempered
  • Anxious
  • Dejected and inadequate
  • Depressed

Disturbed sleep particularly in the elderly, unreasonable impatience, very short attention span, shortness of breath, cravings for sodas and alcoholic beverages are also reported.


Myths and mistaken thinking:

  • Dehydration only occurs in hot weather.
  • If you’re not thirsty you are hydrated.


Water versus other beverages

There’s a difference between drinking pure water and beverages that contain water. Fruit juices and soft drinks contain elements that actually contradict some of the positive effects of the water we drink. Caffeinated beverages act as diuretics, causing us to urinate and robbing our body of necessary water. Soft drinks also contain phosphorus that can lead to depletion of bone calcium. Drinking other beverages to the exclusion of water causes you to lose your taste for water. This is especially true of children.


Water losses

Adults lose nearly 6 pints of water every day. We lose a half a cup to a cup from the soles of our feet.  Another 2 to 4 cups is lost from breathing. Perspiration accounts for another 2 cups. Another three cups are lost in urine.

So let’s do the math. 1 cup + 4 cups + 2 cups+ 3 cups = 10 cups

That’s over 1/2 of a gallon of water lost without any activity! Feeling thirsty?

How much water is enough?

A non-active person needs a half ounce of water per pound of body weight each day. That’s 10- 8 ounce glasses a day if your weight is 160 pounds. An active athletic person needs 2/3 ounce per pound which is 13 to 14- 8 ounce glasses a day if you weigh 160. The more you exercise the more water you need. It takes an average of 64 to 80 ounces to replace the water our bodies lose in 24 hours.

You cannot correct dehydration in a day; it takes weeks. That’s why I counsel people to begin by adding 8 oz a day for one week then increase by 16 oz the next week. For those concerned about having to urinate more frequently, after a few weeks your bladder calms down and you will urinate less frequently but in larger amounts.


References used in this article:

1. Water deprivation headache: a new headache with two variants. Blau, J.N. National Hospital for Neurology and Neurosurgery, London, UK. Headache, 2004; 44(1): 79-83.

2. Triggers of migraine and tension-type headache. Wöber-Bingol, C. Department of Neurology, Medical University of Vienna, Vienna, Austria. Handbook of Clinical Neurology, 2010; 97: 161-172.



5. Water deprivation: a new migraine precipitant. Blau, J.N. The City of London Migraine Clinic, London, UK. Headache, 2005; 45(6): 757-9.

6. You’re not sick you’re thirsty. Batmanghelidj, Dr. F.