Hypernatremia: Causes, Risks, and How It Affects Your Body

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 limits, usually above 145 mEq/L. Also known as high sodium levels, it’s not just a lab number—it’s a sign your body’s fluid balance is off, and it can be life-threatening if ignored. Most cases happen because you lost more water than salt—think heavy sweating, not drinking enough, or illnesses that make you pee too much. It’s common in older adults, people with dementia who can’t ask for water, and those on certain medications that mess with kidney function.

Dehydration, the most frequent trigger of hypernatremia doesn’t always mean you forgot your water bottle. It can come from fever, diarrhea, or even diabetes insipidus, where your body can’t hold onto water properly. Electrolyte disorder, a broader category that includes hypernatremia often shows up quietly—thirst, confusion, muscle weakness—until it’s serious. People on diuretics or those recovering from surgery are especially vulnerable. And while it’s not always obvious, fluid balance, the delicate system that keeps your cells hydrated and functioning is what’s really at stake. When sodium rises, your brain cells shrink. That’s why headaches, seizures, and even coma can happen.

The posts below dig into how medications, chronic conditions, and everyday choices can push sodium levels out of range. You’ll find real-world breakdowns of drugs like tolvaptan used to treat it, how kidney issues tie in, and why some people on long-term diuretics or diabetes meds end up with this problem. You’ll also see how diet, aging, and even hospital stays can disrupt fluid balance. This isn’t theoretical—it’s what doctors see in clinics and ERs every day. Whether you’re managing a condition, caring for someone elderly, or just want to understand what your lab results mean, these guides give you the facts without the fluff.