Hyponatremia: Causes, Symptoms, and Medications That Affect Sodium Levels

When your blood sodium drops too low, you’re dealing with hyponatremia, a condition where sodium levels in the blood fall below 135 mEq/L, disrupting fluid balance and nerve function. Also known as low sodium, it’s not just a lab number—it’s a real risk that can cause confusion, seizures, or even coma if ignored. Sodium isn’t just salt on your food. It’s the key electrolyte that keeps your cells hydrated, your nerves firing, and your muscles working. When it drops, your body starts pulling water into cells to balance things out—and that’s when trouble begins.

Many common medications can trigger hyponatremia. diuretics, drugs like hydrochlorothiazide and furosemide that make you pee more to reduce fluid buildup are the most frequent culprits. They flush out sodium along with water, and if you’re not replacing fluids properly, your sodium levels crash. SSRIs, antidepressants like sertraline and fluoxetine, and antiepileptics, such as carbamazepine and oxcarbazepine also interfere with how your kidneys handle water, leading to dilutional hyponatremia. Even some pain meds and hormone treatments can play a role. It’s not always about drinking too much water—it’s often about how your body holds onto it.

People with heart failure, kidney disease, or adrenal problems are at higher risk, but even healthy adults can develop it—especially older adults or those on multiple meds. Symptoms are sneaky: mild fatigue, headaches, nausea, or muscle cramps might seem like just a bad day. But if you start feeling confused, nauseous, or notice swelling in your hands or feet, it’s not something to wait out. Your doctor can check your sodium level with a simple blood test. Treatment isn’t one-size-fits-all: sometimes it’s just cutting back on fluids, other times it’s adjusting meds or giving IV sodium under supervision.

The posts below cover real cases and comparisons you won’t find in generic health sites. You’ll see how drugs like desonide (a topical steroid) can indirectly affect fluid balance in sensitive patients, how scopolamine and terbutaline interact with electrolyte systems, and why Mestinon and Repaglinide users need to watch for hidden sodium shifts. We also break down how conditions like gastroparesis and thyroid disorders tie into this issue. No fluff. Just clear, practical info on what to ask your doctor, which meds to double-check, and how to spot trouble before it escalates.