Table 2.

Causes, symptoms & treatment of water imbalance

	Common Causes	Symptoms	Treatment
Hypohydration
Isotonic	Vomiting, diarrhoea, diuretics, peritonitis, burns, sedative & carbon monoxide intoxication, sunstroke, haemorrhage	Thirst, fatigue, fainting, collapse, vomiting, hypotonia, muscle cramps, rapid pulse	Isotonic salt solutions
Hypotonic	Inadequate sodium intake after vomiting, diarrhoea, sweating. Increased sodium losses due to adrenal failure, chronic diuretic therapy, diarrhoea, heat exhaustion.	Fatigue, fainting, hypotonia, vomiting, collapse, fever, muscle cramps, rapid pulse, depressed consciousness level, ‘shock’, confusion	Sodium chloride +/− isotonic saline
Hypertonic	Inadequate water intake, sweating, watery diarrhoea, osmotic diuretics, hyperventilation, chronic nephropathy, polyuric phase of acute renal failure, diabetes insipidus, prolonged nil by mouth, tube feeding with inadequate water	Decreased skin turgor, dry mucous membranes, thirst, fever, restlessness, delirium, coma	Pure water or glucose solution
Hyperhydration
Isotonic	Excessive administration of isotonic infusion solutions in oliguric or anuric states, cardiac failure, nephrotic syndrome, chronic uraemia, acute glomerulonephritis, liver cirrhosis	Oedema, effusions, hypertension dyspnoea	Sodium chloride Fluid restriction Diuretics Osmotic therapy
Hypotonic	Excess administration of salt-free solutions, gastric lavage with water, increased ADH activity, liver failure	Weakness, nausea, vomiting, dyspnoea, confusion, loss of consciousness, headache, photophobia, muscle twitching, hyperirritability, polyuria, convulsions	Fluid restriction Dialysis Sodium chloride if tendency to alkalosis
Hypertonic	Drinking sea water, overactivity of renal cortex in Conn’s syndrome, Cushing’s syndrome, administration of steroids, hypertonic tube feeding (no flush), hypertonic enemas, excessive administration of sodium chloride.	Vomiting, diarrhoea, labile blood pressure, pulmonary oedema, restlessness, changes in central venous pressure	Sodium chloride & fluid restriction Diuretics Osmotic therapy