Severe Hyponatremia: What It Is and How to Manage It

When working with severe hyponatremia, a dangerous drop in blood sodium level below 120 mmol/L that can cause brain swelling and life‑threatening symptoms. Also known as critical sodium deficiency, it requires urgent medical attention to prevent permanent damage. This condition often shows up after a bout of excessive water intake, certain medications, or hormonal imbalances. For example, SIADH (syndrome of inappropriate antidiuretic hormone secretion) forces the kidneys to retain water, diluting sodium and setting the stage for severe hyponatremia. Likewise, high‑dose diuretics (medications like furosemide that increase urine output) can strip the body of electrolytes faster than they are replenished, especially when combined with a low‑sodium diet. The brain is particularly sensitive, so symptoms range from mild headache and nausea to confusion, seizures, and coma. Recognizing the early signs—headache, nausea, muscle cramps—can be the difference between a quick fix and a critical emergency.

Key Factors and Management Strategies

The core of treatment revolves around three pillars. First, severe hyponatremia demands careful correction of sodium levels; doctors often use hypertonic saline (a high‑concentration salt solution administered intravenously) to raise serum sodium at a controlled rate, avoiding rapid shifts that could harm brain cells. Second, restricting fluid intake—known as fluid restriction (limiting daily water consumption to prevent further dilution)—helps the body retain the sodium it receives. Third, addressing the underlying cause, whether it’s stopping a problematic diuretic, treating SIADH with medication like demeclocycline, or adjusting the patient’s diet to include adequate sodium, is essential for lasting recovery. These strategies illustrate a clear semantic chain: severe hyponatremia results from water excess, fluid restriction counters the excess, and hypertonic saline directly raises sodium levels. Each step connects to the next, forming a coherent treatment roadmap.

Beyond the acute phase, patients often need ongoing monitoring. Serum sodium checks, blood pressure control, and education on safe fluid habits keep the condition from returning. Lifestyle tweaks—like moderating excessive water drinking during endurance sports and reviewing medication lists with a pharmacist—play a big role. In many cases, the same drugs that cause hyponatremia, such as certain heart‑failure diuretics, are still needed, so dose adjustments and close follow‑up become part of the long‑term plan. By understanding the causes, recognizing the warning signs, and applying targeted therapies, you can navigate severe hyponatremia confidently.

Below you’ll find a curated selection of articles that dive deeper into each of these areas, from the science behind SIADH to practical tips on fluid management and medication choices. Explore the guides to get a clearer picture of how to spot, treat, and prevent severe hyponatremia in everyday health scenarios.