Fluid and Electrolyte Balance Test Exam
Merged With Correct Verified Solutions
Graded A+ | 2026 Latest Update!!!
1. Which electrolyte is primarily responsible for maintaining
extracellular fluid volume?
A. Potassium
B. Calcium
C. Sodium
D. Magnesium
Answer: C. Sodium
Rationale: Sodium is the major electrolyte found in extracellular fluid
and plays the primary role in regulating water balance, osmotic
pressure, and blood volume. Abnormal sodium levels can significantly
affect hydration status and neurological function.
2. Which condition is commonly associated with dehydration?
A. Bradycardia
B. Weight gain
C. Dry mucous membranes
D. Bounding pulse
Answer: C. Dry mucous membranes
,Rationale: Dry mucous membranes are a classic sign of dehydration
due to reduced body fluid volume. Other signs include decreased skin
turgor, tachycardia, hypotension, and concentrated urine.
3. Which electrolyte imbalance is most commonly seen in patients
taking loop diuretics?
A. Hyperkalemia
B. Hypokalemia
C. Hypercalcemia
D. Hypermagnesemia
Answer: B. Hypokalemia
Rationale: Loop diuretics increase urinary excretion of potassium,
placing patients at risk for hypokalemia. Low potassium levels can
cause muscle weakness, cardiac dysrhythmias, and fatigue.
4. Which hormone helps regulate water balance by increasing
water reabsorption in the kidneys?
A. Aldosterone
B. Insulin
C. Antidiuretic hormone
D. Parathyroid hormone
Answer: C. Antidiuretic hormone
Rationale: Antidiuretic hormone (ADH) promotes water reabsorption
in the renal tubules, helping maintain fluid balance and blood
pressure. Increased ADH secretion reduces urine output and
conserves water.
5. A patient with hypernatremia is most likely to exhibit which
symptom?
,A. Confusion
B. Muscle tetany
C. Diarrhea
D. Slow reflexes
Answer: A. Confusion
Rationale: Hypernatremia causes cellular dehydration, especially in
brain cells, leading to neurological symptoms such as confusion,
irritability, restlessness, and seizures in severe cases.
6. Which laboratory value indicates normal serum potassium?
A. 2.1 mEq/L
B. 3.8 mEq/L
C. 5.9 mEq/L
D. 6.3 mEq/L
Answer: B. 3.8 mEq/L
Rationale: Normal serum potassium ranges from 3.5 to 5.0 mEq/L.
Potassium is essential for nerve conduction, muscle contraction, and
cardiac function.
7. Which clinical finding is associated with hypocalcemia?
A. Positive Chvostek sign
B. Hypertension
C. Bradycardia
D. Warm flushed skin
Answer: A. Positive Chvostek sign
Rationale: Hypocalcemia increases neuromuscular excitability,
causing signs such as Chvostek sign, Trousseau sign, muscle cramps,
and tetany.
, 8. Which intravenous solution is considered isotonic?
A. 0.45% normal saline
B. 3% saline
C. Dextrose 5% in water
D. 0.9% normal saline
Answer: D. 0.9% normal saline
Rationale: Isotonic solutions have an osmolarity similar to plasma and
do not cause fluid shifts between compartments. Normal saline is
commonly used for fluid replacement and volume expansion.
9. Which patient is at greatest risk for fluid volume overload?
A. A patient with heart failure
B. A patient with diarrhea
C. A patient with vomiting
D. A patient with burns
Answer: A. A patient with heart failure
Rationale: Heart failure impairs the heart’s ability to pump effectively,
leading to fluid retention and overload. Symptoms may include edema,
crackles, and shortness of breath.
10. Which electrolyte plays a major role in muscle
contraction and cardiac rhythm?
A. Phosphate
B. Potassium
C. Chloride
D. Sodium bicarbonate
Answer: B. Potassium
Merged With Correct Verified Solutions
Graded A+ | 2026 Latest Update!!!
1. Which electrolyte is primarily responsible for maintaining
extracellular fluid volume?
A. Potassium
B. Calcium
C. Sodium
D. Magnesium
Answer: C. Sodium
Rationale: Sodium is the major electrolyte found in extracellular fluid
and plays the primary role in regulating water balance, osmotic
pressure, and blood volume. Abnormal sodium levels can significantly
affect hydration status and neurological function.
2. Which condition is commonly associated with dehydration?
A. Bradycardia
B. Weight gain
C. Dry mucous membranes
D. Bounding pulse
Answer: C. Dry mucous membranes
,Rationale: Dry mucous membranes are a classic sign of dehydration
due to reduced body fluid volume. Other signs include decreased skin
turgor, tachycardia, hypotension, and concentrated urine.
3. Which electrolyte imbalance is most commonly seen in patients
taking loop diuretics?
A. Hyperkalemia
B. Hypokalemia
C. Hypercalcemia
D. Hypermagnesemia
Answer: B. Hypokalemia
Rationale: Loop diuretics increase urinary excretion of potassium,
placing patients at risk for hypokalemia. Low potassium levels can
cause muscle weakness, cardiac dysrhythmias, and fatigue.
4. Which hormone helps regulate water balance by increasing
water reabsorption in the kidneys?
A. Aldosterone
B. Insulin
C. Antidiuretic hormone
D. Parathyroid hormone
Answer: C. Antidiuretic hormone
Rationale: Antidiuretic hormone (ADH) promotes water reabsorption
in the renal tubules, helping maintain fluid balance and blood
pressure. Increased ADH secretion reduces urine output and
conserves water.
5. A patient with hypernatremia is most likely to exhibit which
symptom?
,A. Confusion
B. Muscle tetany
C. Diarrhea
D. Slow reflexes
Answer: A. Confusion
Rationale: Hypernatremia causes cellular dehydration, especially in
brain cells, leading to neurological symptoms such as confusion,
irritability, restlessness, and seizures in severe cases.
6. Which laboratory value indicates normal serum potassium?
A. 2.1 mEq/L
B. 3.8 mEq/L
C. 5.9 mEq/L
D. 6.3 mEq/L
Answer: B. 3.8 mEq/L
Rationale: Normal serum potassium ranges from 3.5 to 5.0 mEq/L.
Potassium is essential for nerve conduction, muscle contraction, and
cardiac function.
7. Which clinical finding is associated with hypocalcemia?
A. Positive Chvostek sign
B. Hypertension
C. Bradycardia
D. Warm flushed skin
Answer: A. Positive Chvostek sign
Rationale: Hypocalcemia increases neuromuscular excitability,
causing signs such as Chvostek sign, Trousseau sign, muscle cramps,
and tetany.
, 8. Which intravenous solution is considered isotonic?
A. 0.45% normal saline
B. 3% saline
C. Dextrose 5% in water
D. 0.9% normal saline
Answer: D. 0.9% normal saline
Rationale: Isotonic solutions have an osmolarity similar to plasma and
do not cause fluid shifts between compartments. Normal saline is
commonly used for fluid replacement and volume expansion.
9. Which patient is at greatest risk for fluid volume overload?
A. A patient with heart failure
B. A patient with diarrhea
C. A patient with vomiting
D. A patient with burns
Answer: A. A patient with heart failure
Rationale: Heart failure impairs the heart’s ability to pump effectively,
leading to fluid retention and overload. Symptoms may include edema,
crackles, and shortness of breath.
10. Which electrolyte plays a major role in muscle
contraction and cardiac rhythm?
A. Phosphate
B. Potassium
C. Chloride
D. Sodium bicarbonate
Answer: B. Potassium
