The extremes of hydration

Dehydration

Dehydration means your body loses more fluid than it takes. Dehydration can be mild, moderate or severe depending on the amount of water lost from the body.

Severe dehydration can be fatal if not treated at the earliest. Since most of the body’s function depends on the water, even a mild dehydration affects these function¹⁹ giving symptoms like fatigue, dizziness, dry mouth, excessive thirst and so on.

Causes

There can be a number of causes leading to dehydration -

• Fever - long duration fever
• Diarrhoea
• Vomiting
• Excessive sweating - either due to a strenuous exercise/work in a hot climate, exposed to sun for a long period of time without rehydrating yourself sufficiently.

Who are prone to dehydration

• Children and elderly
• Athletes especially marathoners if they don't rehydrate themselves sufficiently
• Diabetics
• Being in the sun for too long
• Those who are on medications that increase urination (diuretics)

Symptoms

Mild to moderate dehydration can lead to -

• Dryness of mouth and dry/cracked lips
• Decrease in urination
• Headache
• Thirst
• Muscle cramps
• Dark coloured urine

Severe dehydration can result in -

• Dry skin
• Heavy and rapid breathing
• Dizziness or drowsiness
• Confusion or irritability
• Fainting
• Rapid heart beat

Dehydration in children and elderly should be taken special care since they don't show typical symptoms of mild dehydration and the condition can become severe in a matter of time.

In elderly, the thirst response gets blunted with age and secondly, there is also a decline in kidney function in some elderly people, making them more susceptible to dehydration. The symptoms would be somewhat similar to those observed in adults and the management involves keeping them well hydrated with fluids.

In children, it is required to take them to a hospital nearby if they display symptoms²⁰ as -

• seem drowsy and irritable
• breathe fast
• have few or no tears when they cry
• have a soft spot on their head that sinks inwards (sunken fontanelle)
• have a dry mouth
• have dark coloured urine
• have cold and blotchy-looking hands and feet
• Dry diapers for more than three hours

Treatment of dehydration

Mild to moderate dehydration can be treated at home using an oral re-hydration solution (ORS). It is prepared by mixing 6 tsp of sugar + ½ tsp of salt added to 1 litre of boiled and cooled water.  More details regarding ORS can be found at the WHO guidelines for treating dehydration.

Dehydration symptoms - thirst, headache, decrease in urination, dark coloured urine, dizziness, dry mouth and cracked lips

ORS to manage dehydration - It is prepared by mixing 6 tsp of sugar + ½ tsp of salt added to 1 litre of boiled and cooled water.

Do’s and don'ts of managing dehydration

Do’s

• Administer ORS (either prepared at home or use of ready made sachets).
• If there is vomiting or diarrhoea, give the same amount lost by the body. If 1 cup of water is lost during vomiting, replace with the same amount orally.
• Antiemetic (medicines that stop vomiting) can be given on the advice of a general physician if vomiting is present
• If oral intake is not possible due to some reason, it is better to get admitted in the hospital in cases of chronic dehydration.
• Once the urinary output comes to normalcy, include fruits rich in potassium like bananas, musk melon to balance the electrolytes. Cereals like rice ganji with buttermilk (thick rice gruel diluted with buttermilk) can be given as a probiotic and also for energy.
• For infants, breastfeeding should be continued with small sips of boiled and cooled water in between
• For older children, they should be encouraged to drink the ORS and their urinary output should be monitored. Every loss should be replaced with an equal amount of fluid till the urine output becomes normal with light coloured urine.

Don’ts

• Avoid any fizzy drinks or juices or any drinks with high sugar content. Sugar can worsen the existing diarrhoea aggravating the condition.
• Avoid taking tea or coffee till the body’s hydration levels comes to normal. Buttermilk with a pinch of salt is a much better option for mild case of dehydration.
• Avoid taking solid food or fatty foods which are difficult to digest and which requires more water to digest especially when one is dehydrated.
• Avoid going out for some time till the body is rehydrated, take ample rest and allow the body to gain its equilibrium.

Prevention

Here are some tips to prevent dehydration -

• Drinking 8-10 glasses of water daily takes care of the fluid requirement of the body
• Make a habit of including fruits and vegetables with high moisture content daily in the diet. You can include watermelon, muskmelon, oranges, sweet lime, grapefruit, cucumber, tomatoes, tender coconut water. These not only add to the water content but they also contain salts like sodium and potassium which can keep the electrolytes in balance.
• While travelling, always carry a bottle of water to quench the thirst.
• During hot climate, wear cotton clothes since cotton is a porous material and allows for air to pass through keeping the body cool.
• During summer, avoid any strenuous activity outdoors. Always rehydrate yourself with plain water (avoid cold water or juices directly from the fridge) once you get back after an outdoor activity.
• During summer time, reduce the intake of caffeinated beverages and alcohol since they have a dehydrating effect on the body. The best option to go for is the buttermilk with little salt and spices like cumin, ginger and pepper or a simple lemonade with salt and sugar.
• Children and elderly should be given a bottle of water and their intake should be monitored.

Overhydration

Overhydration also called water intoxication is very rare and happens when you drink excess water than your kidneys can excrete.

Overhydration can result due to the following -

• Over consumption - drinking more water in a short period of time where the kidneys are not able to eliminate such large quantity. Very commonly seen in athletes involved in long duration workout and endurance training. Since they lose a lot of water during their exercise, they may take in more water than the body can eliminate leading to intoxication.

This condition is also seen in some psychiatric patients where water intoxication is self induced.

• Over Retention - when your body is not able to eliminate water due to some medical condition. This is commonly seen in people with congestive heart failure, kidney disease, uncontrolled diabetes, liver disorder, those on non steroidal anti inflammatory drugs.

Over hydration leads to a condition called hypo-natremia (low sodium levels) in the body which can affect the brain and can even be fatal if proper course of treatment is not given in time.

Prevent over hydration by drinking water when thirsty. Gulping down litres of water just because it is good for health is not advisable and can be even fatal.

Symptoms

Include nausea, vomiting and headache, mental disorientation and confusion can also occur.

In severe cases, symptoms can range from fatigue, muscle cramps, loss of appetite to seizures and coma.

Management and prevention

Treatment depends on the severity of the condition and the cause. Treatments may include:

• cutting back on your fluid intake
• treating the condition that caused the overhydration
• stopping any medications causing the problem
• May require hospitalisation and fluid transfusion to correct electrolyte imbalance.

Prevention

• For athletes, weighing themselves before and after the training, helps to decide the amount of water to be ingested. It is recommended to drink 500ml of water for every 1-1.5kg loss of weight.
• For normal individuals, let thirst be the indicator of fluid intake. If you feel thirsty, drink water.
• Those with medical conditions should check with their doctor regarding the fluid intake and also if they have excessive thirst.

In a nutshell, both under dehydration and overhydration are dangerous conditions and the best way to avoid both these conditions is to be mindful while drinking water. Let thirst decide the amount of water that you need to take. Secondly, those with any underlying medical condition should get themselves evaluated periodically.

References

19 mild-dehydration-impairs-cognitive-performance-and-mood-of-men

20 https://www.nhs.uk/conditions/dehydration/