Question 44:
Hyponatremia is a condition where the concentration of the following ion decreases below normal level in plasma:
The correct answer is (A) Sodium.
Hyponatremia specifically refers to a low concentration of sodium ions in the plasma, typically below 135 mEq/L, disrupting fluid balance and cellular function.
Option Breakdown
(A) Sodium
This is the defining feature of hyponatremia, where plasma sodium drops due to dilution from excess water, sodium loss (e.g., via sweat or diuretics), or conditions like heart failure. Symptoms range from mild (headache, fatigue) to severe (seizures, coma).
(B) Potassium
Low potassium is called hypokalemia, which affects heart rhythm and muscles but is distinct from hyponatremia; both can coexist in electrolyte imbalances.
(C) Zinc
Zinc deficiency leads to hypozincemia, impacting immunity and wound healing, but it’s not measured in routine plasma electrolyte panels like sodium.
(D) Magnesium
Hypomagnesemia involves low magnesium, causing arrhythmias or tremors, unrelated to the sodium-specific term hyponatremia.
Introduction to Hyponatremia Low Sodium Plasma
Hyponatremia low sodium plasma occurs when sodium concentration falls below 135 mEq/L, often due to water imbalance rather than sodium deficit alone. Vital for biology students tackling GATE Life Sciences, it contrasts with other ion deficiencies.
Causes and Symptoms of Hyponatremia
Excess water intake, medications, or diseases like kidney failure dilute plasma sodium, triggering nausea, confusion, and muscle cramps. Severe cases risk brain swelling from osmotic shifts.
Normal plasma sodium is 135-145 mEq/L; rapid drops worsen outcomes.
Hyponatremia vs Other Ions: Exam Comparison
| Option | Condition Name | Plasma Effect | Common Symptoms |
|---|---|---|---|
| Sodium | Hyponatremia | <135 mEq/L | Headache, seizures |
| Potassium | Hypokalemia | Low K+ | Arrhythmias, weakness |
| Zinc | Hypozincemia | Low trace metal | Immune issues, hair loss |
| Magnesium | Hypomagnesemia | Low Mg2+ | Tremors, hypocalcemia |
This breakdown clarifies why sodium defines hyponatremia in competitive exams.
Relevance for Life Sciences Students
Understanding hyponatremia low sodium plasma aids in physiology and biochemistry sections, emphasizing electrolyte homeostasis disrupted by ADH or renal issues.
