ADVANCED PATHOPHYSIOLOGY EXAM 2026 – KEY
CONCEPTS & MECHANISMS STUDY GUIDE (A+ PREP)
causes of hypovolemia
- loss of fluids from anywhere (thoracentisis, paracentisis, vomiting, diarrhea, hemorrhage,
suction)
- Third spacing (burns, ascites)
- diseases with polyuria (polyuria > oliguria > anuria > renal failure)
clinical manifestations of hypovolemia
-Thirst
-Dry mucous membranes
-Decreased skin turgor/delay return/tenting
-Hypotension, tachycardia
-Weight loss
-Decreased urine output, concentrated urine
-Restless, drowsy, confused, dizzy, weak
total body water
-usually expressed as a percentage of body weight
-varies based on body type, sex, and age
-female normal build 50% water
-male normal build 60% water
,causes of hypervolemia
Heart failure
Kidney disease
Cirrhosis
Overdose of sodium concentrated fluids
Fluid shifts in burns
Prolonged use of corticosteroids
Severe stress
Hyperaldosteronism
weight gain
manifestations of hypervolemia
-Edema pitting
-pulmonary congestion
-circulatory overload( bounding pulses, jugular vein distention, elevated blood pressure
- weight gain
hypernatremia
occurs when serum sodium levels exceed 145 mEq/L and causes hypertonicity
hypovolemic hypernatremia
occurs where there is loss of body sodium accompanied by a relatively greater loss of body
water
,causes: loop diuretics, osmotic diuresis (ie from hyperglycemia related to uncontrolled
diabetes or mannitol), GI losses, failure of kidneys to concentrate urine
Euvolemic hypernatremia
most common
occurs when there is a loss of free water with a near normal sodium concentration
causes: inadequate water intake, excessive sweating, fever with hyperventilation and water
loss from burns, vomiting, diarrhea, diabetes insipidus
hypervolemic hypernatremia
rare
occurs when there is increased TBW and greater increase in total body sodium level,
resulting in hypervolemia
causes: infusion of hypertonic saline solutions, over-secretion of ACTH or aldosterone
(cushing syndrome)
signs of hypernatremia
weakness
lethargy
muscle twitching
hyperreflexia due to shrinking of brain cells and alterations in membrane potential
labs of hypernatremia
, hematocrit and plasma protein levels are elevated with water loss
sodium >145
hyponatremia
develops when the serum sodium concentration decreases to less than 135 mEq/L
most common electrolyte disorder in hospitalized individuals
occurs when there is a loss of sodium, inadequate intake of sodium, or dilution of sodium
by water excess
excessive diuretic therapy
hyponatremia ECF effects
extracellular volume contraction and hypovolemia
hyponatremia ICF effects
increased intracellular water, edema, brain cell swelling, irritability, depression, confusion,
systemic cellular edema (weakness, anorexia, nausea, diarrhea)
hypovolemic hyponatremia
with pure sodium loss is accompanied by loss of ECF with symptoms of hypotension,
tachycardia, decreased urine output
hypervolemic hyponatremia
CONCEPTS & MECHANISMS STUDY GUIDE (A+ PREP)
causes of hypovolemia
- loss of fluids from anywhere (thoracentisis, paracentisis, vomiting, diarrhea, hemorrhage,
suction)
- Third spacing (burns, ascites)
- diseases with polyuria (polyuria > oliguria > anuria > renal failure)
clinical manifestations of hypovolemia
-Thirst
-Dry mucous membranes
-Decreased skin turgor/delay return/tenting
-Hypotension, tachycardia
-Weight loss
-Decreased urine output, concentrated urine
-Restless, drowsy, confused, dizzy, weak
total body water
-usually expressed as a percentage of body weight
-varies based on body type, sex, and age
-female normal build 50% water
-male normal build 60% water
,causes of hypervolemia
Heart failure
Kidney disease
Cirrhosis
Overdose of sodium concentrated fluids
Fluid shifts in burns
Prolonged use of corticosteroids
Severe stress
Hyperaldosteronism
weight gain
manifestations of hypervolemia
-Edema pitting
-pulmonary congestion
-circulatory overload( bounding pulses, jugular vein distention, elevated blood pressure
- weight gain
hypernatremia
occurs when serum sodium levels exceed 145 mEq/L and causes hypertonicity
hypovolemic hypernatremia
occurs where there is loss of body sodium accompanied by a relatively greater loss of body
water
,causes: loop diuretics, osmotic diuresis (ie from hyperglycemia related to uncontrolled
diabetes or mannitol), GI losses, failure of kidneys to concentrate urine
Euvolemic hypernatremia
most common
occurs when there is a loss of free water with a near normal sodium concentration
causes: inadequate water intake, excessive sweating, fever with hyperventilation and water
loss from burns, vomiting, diarrhea, diabetes insipidus
hypervolemic hypernatremia
rare
occurs when there is increased TBW and greater increase in total body sodium level,
resulting in hypervolemia
causes: infusion of hypertonic saline solutions, over-secretion of ACTH or aldosterone
(cushing syndrome)
signs of hypernatremia
weakness
lethargy
muscle twitching
hyperreflexia due to shrinking of brain cells and alterations in membrane potential
labs of hypernatremia
, hematocrit and plasma protein levels are elevated with water loss
sodium >145
hyponatremia
develops when the serum sodium concentration decreases to less than 135 mEq/L
most common electrolyte disorder in hospitalized individuals
occurs when there is a loss of sodium, inadequate intake of sodium, or dilution of sodium
by water excess
excessive diuretic therapy
hyponatremia ECF effects
extracellular volume contraction and hypovolemia
hyponatremia ICF effects
increased intracellular water, edema, brain cell swelling, irritability, depression, confusion,
systemic cellular edema (weakness, anorexia, nausea, diarrhea)
hypovolemic hyponatremia
with pure sodium loss is accompanied by loss of ECF with symptoms of hypotension,
tachycardia, decreased urine output
hypervolemic hyponatremia
