Dehydration | Hydralyte

  • What is dehydration?

  • What are the signs of dehydration?

  • Why do we need electrolytes and glucose when dehydrated?

  • Why are soft drinks, sports drinks and juice unsuitable for rehydration?

What is Dehydration?

To function correctly and remain healthy, our body requires the correct internal balance of water and electrolytes. Every day our body loses fluid and electrolytes via urine, sweat, saliva, and other bodily fluids. Usually, a normal, healthy diet will serve to replace lost electrolytes and fluid.

Certain conditions such as a bout of vomiting and diarrhoea, heavy sweating, or ongoing lack of intake of food and drink can lead to inadequate levels of fluid and electrolytes within our bodies. This is called dehydration.

We only have to lose as little as 2% of our body weight rapidly and signs of dehydration will become apparent.

What are the signs of mild to moderate dehydration?

  • Decreased urine output (or darker in colour than usual)
  • Lethargy
  • Dry mouth
  • Loss of skin elasticity (white marks will appear if pinched)
  • Sunken eyes
  • Sunken fontanelle (soft spot on babies head)
  • Headache
  • Rapid body weight loss of 2% - 7%.

What role do glucose and electrolytes play in rehydration?

Glucose and electrolytes (sodium, potassium, chloride) serve several functions:

  • they replace the electrolytes that have been lost due to the dehydrating conditions
  • Glucose provides a source of energy that may be lacking
  • together, glucose and sodium help draw water rapidly into the bloodstream from the small intestine (like a pump)
  • Electrolytes help retain the fluid

Why are soft drinks, sports drinks and juice unsuitable for rehydration?

Rapid rehydration and fluid retention depend on the right levels of glucose (sugar) and electrolytes (particularly sodium) in the solution.

Usually these beverages have too much sugar and not enough sodium. This can interfere with the rehydration process.

Hydralyte has been formulated to contain the correct concentration of these active ingredients.

Ingredient Function within the body Hydralyte Sports Drink (approx)
 Sodium Helps body to
retain fluid
 Potassium Essential for
nerve and
muscle funtion
20mmol/L 4mmol/L
 Chloride Helps body to
retain fluid
45mmol/L N/A
 Citrate Natural Flavour
and help stop
30mmol/L N/A
 Carbohydrates Assists
electrolyte and
water absorption
(energy source)


For further information on  other causes of dehydration go to:


Always read the label and use only as directed. If symptoms persist see your healthcare professional.