Hypernatremia: Causes, Risks, and What Your Medications Might Be Doing

When your blood sodium levels climb too high, you're dealing with hypernatremia, a condition where the concentration of sodium in the blood exceeds normal levels, usually due to water loss or excess sodium intake. Also known as high sodium blood, it's not something you can feel until it's already affecting your brain, kidneys, or heart. Most people don’t realize how easily this happens—especially if they’re older, taking diuretics, or just not drinking enough water on hot days.

Hypernatremia often shows up alongside dehydration, a state where the body loses more fluid than it takes in, leading to reduced blood volume and impaired organ function. Think of it like saltwater in a shrinking pool—the salt stays, but the water disappears. Common triggers include fever, vomiting, diarrhea, or even overuse of salt-based laxatives. But here’s what’s often missed: some medications make it worse. Diuretics like hydrochlorothiazide, used for high blood pressure, push water out of your body. If you’re not replacing that fluid, sodium builds up. Even some psychiatric drugs and lithium can mess with your kidneys’ ability to hold onto water.

It’s not just about thirst. Older adults, especially those with dementia or limited mobility, may not feel thirsty even when their body is screaming for water. That’s why hypernatremia shows up in hospitals more often in nursing homes than you’d expect. Your kidneys also play a big role—if they’re not working right, they can’t concentrate urine to save water. This links directly to conditions like kidney function, the ability of the kidneys to filter waste and regulate electrolytes like sodium and potassium in the blood. If you’re on meds that affect kidney flow—like NSAIDs or certain blood pressure drugs—you’re at higher risk.

What you’ll find here isn’t just textbook definitions. These are real cases: someone on losartan-hydrochlorothiazide who didn’t drink enough water and ended up confused; a senior on diuretics who skipped fluids during a heatwave; a patient taking tramadol who developed seizures because hypernatremia lowered their seizure threshold. These aren’t rare. They’re preventable. And they’re all tied to how your body handles sodium, water, and the drugs you take every day.

Below, you’ll find guides that connect the dots between your medications, your fluid balance, and your health. Whether you’re managing high blood pressure, dealing with side effects from antibiotics, or just trying to stay safe while aging, the right info can stop hypernatremia before it starts.