Babies fed too much water can develop seizures because of a rare condition called water intoxication. Given numerous bottles of water or a very dilute baby formula to a baby under the age of 6 months can cause water intoxication. When the infant is hungry and just gulps the formula or water down, the infant's tissues swell with the excess fluid. When the serum sodium level drops, their eyes begin to flutter and a seizure occurs.
The dilution of infant formula with water can cause water intoxication in infancy. Some parents cannot afford formula and will give their babies water to drink. They baby feels satisfied after the drinking of the water and that makes the mother or caregivers think that water is enough for the hungry infant. Formulas are often diluted with water, this can also cause Kwashiorkor due to a protein deficiency. The child seems well fed because of the child's distended abdomen.
I was working as a professional nurse for many years and saw the consequences of diluted formulas or even 'mealie pap' given in a very diluted form to hungry infants.
Babies do not need extra water
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A thirsty person usually has a dry mouth, which is a consequence of the loss of extracellular water and resulting decreased flow of saliva.
Thirst is the primary regulator of water intake. "The intense feeling of thirst derives from the osmotic pressure of extracellular fluids and a thirst center in the hypothalamus of the brain. The thirst mechanism is normally triggered whenever the total body water is decreased by as little as 1%." Ricki Lewis
Too much water
If a person drinks too much water, the plasma becomes less concentrated and the osmoreceptors swell as they receive extra water by osmosis.
Nerve impulses that inhibit the thirst mechanisms are triggered when the stomach wall is distended after the drinking of water, drinking water stops long before the swallowed water is absorbed. This inhibition stops the person from drinking more than is required to replace the quantity lost, avoiding development of an imbalance of the opposite type.
Osmotic Pressure
Hypotonic hydration
- Renal insufficiency or an extraordinary amount of water ingested quickly can lead to cellular overhydration or water intoxication
- Extracellular fluid is diluted, sodium content is normal but excess water present
- Hyponatremia results and promotes osmosis into cells, causing swelling
- Nausea, vomiting, muscular cramping, cerebral edema, disorientation, convulsions, coma, and death are the results of overhydration
Sources:https://en.wikipedia.org/wiki/Kwashiorkor#/
https://sciencing.com/happens-cells-dehydrated-23904.html