Hypernatremia: Causes, Risks, and How Medications Affect Sodium Levels

When your blood sodium gets too high, you have hypernatremia, a condition where sodium levels in the blood rise above 145 mEq/L, often due to fluid loss or inadequate water intake. Also known as high sodium blood levels, it’s not just a lab number—it’s a signal your body is struggling to balance fluids, and it can turn dangerous fast, especially in older adults or infants. Sodium isn’t bad—it’s essential for nerve function, muscle contractions, and keeping your cells hydrated. But when you lose too much water through sweating, diarrhea, or even just not drinking enough, that sodium becomes too concentrated. The result? Thirst, confusion, muscle weakness, and in severe cases, seizures or coma.

Medications play a big role in triggering or worsening hypernatremia, a potentially life-threatening electrolyte imbalance caused by excessive sodium or insufficient water. Diuretics like furosemide can flush out too much water, leaving sodium behind. Lithium, used for bipolar disorder, can mess with your kidneys’ ability to concentrate urine. Even some antibiotics and antipsychotics can interfere with how your body holds onto water. And if you’re on multiple meds—especially for chronic conditions like heart failure or diabetes—you might not realize your pills are quietly raising your sodium. It’s not always obvious. You might feel fine until you suddenly can’t think straight.

It’s not just about what you take—it’s about what you don’t drink. Older people often lose their sense of thirst. Babies can’t tell you they’re dry. People with dementia or mobility issues might not reach for water. That’s why dehydration, a state of fluid loss that leads to concentrated blood sodium and electrolyte imbalance is the most common root cause. But it’s also why hypernatremia is so preventable. Catch it early, and it’s often fixed with simple rehydration. Miss it, and it can lead to brain swelling, permanent damage, or worse.

You’ll find posts here that connect the dots between sodium imbalance and real-world medication use. From infant drops and liquid medicine safety to how certain drugs interact with kidney function and fluid balance, these articles don’t just explain the science—they show you how it plays out in daily life. Whether you’re caring for a child, managing chronic illness, or just trying to understand why your doctor asked about your water intake, this collection gives you the practical info you need to spot trouble before it escalates.