Hyponatremia: Causes, Risks, and How Medications 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 mmol/L, disrupting fluid balance and nerve function. Also known as low sodium, it’s not just about drinking too much water—it’s often tied to how your body handles fluids because of medications, illness, or hormonal changes. Sodium isn’t just table salt—it’s critical for keeping your nerves, muscles, and brain working right. When levels slip, you might feel dizzy, nauseous, or confused. In severe cases, it can trigger seizures, coma, or even death.

Many common drugs can cause or worsen hyponatremia. diuretics, medications that make you pee more to reduce fluid buildup. Also known as water pills, they’re often prescribed for high blood pressure or heart failure, but they can flush out too much sodium along with water. antidiuretic hormone, a natural hormone that tells your kidneys to hold onto water. Also known as ADH, it’s overactive in some people due to illness or certain drugs, leading to water retention and diluted sodium. SSRIs, some pain meds, and even MDMA can trigger this. Even something as simple as drinking too much water during a marathon can throw your sodium off—if your body can’t excrete the extra fluid fast enough.

Hyponatremia doesn’t always show up with obvious symptoms. Some people feel fine until it’s too late. That’s why it’s often found during routine blood tests, especially in older adults or those on long-term meds. If you’re taking diuretics, have heart or kidney disease, or notice unexplained fatigue and headaches, it’s worth asking your doctor to check your sodium. The fix isn’t always just adding salt—it’s about fixing the root cause, whether that’s adjusting meds, treating an underlying condition, or changing fluid intake habits.

The posts below dive into how specific drugs, supplements, and health conditions interact with your body’s electrolyte balance. You’ll find real-world examples of how medications like diuretics or antipsychotics can trigger sodium drops, what tests actually show, and how to spot early warning signs before things get serious. This isn’t theoretical—it’s about protecting your health with clear, practical info.