SSRI Hyponatremia: Risks, Symptoms, and What You Need to Know

When you take an SSRI, a class of antidepressants that increase serotonin in the brain to improve mood. Also known as selective serotonin reuptake inhibitors, these drugs include Lexapro, Zoloft, Prozac, and Celexa—medications millions use daily to manage depression and anxiety. But behind their effectiveness lies a less talked-about risk: hyponatremia, a condition where sodium levels in the blood drop too low. This isn’t rare—it happens often enough that doctors now screen for it in patients starting SSRIs, especially older adults and women. The connection isn’t theoretical. Studies show up to 1 in 10 people on SSRIs develop mild hyponatremia within the first few weeks, and some cases turn dangerous if missed.

How does an antidepressant mess with your sodium? SSRIs can trigger a hormone called ADH to stay active longer than it should. That tells your kidneys to hold onto water instead of flushing it out. Too much water in your blood dilutes sodium, and suddenly your body’s electrolyte balance is off. Symptoms? They’re easy to miss: mild nausea, headaches, feeling dizzy when you stand up, or just being more tired than usual. In older adults, confusion or falls can be the first red flag. It’s not always dramatic—sometimes it’s just a quiet, creeping change that gets blamed on aging or stress.

Some people are more at risk than others. If you’re over 65, take diuretics, or have heart or kidney issues, your chances go up. Women, especially those who are postmenopausal, are also more likely to develop this. It’s not about the dose—even low doses of SSRIs can cause it. And it doesn’t always show up right away. Some cases develop after months on the drug, which is why ongoing monitoring matters.

You don’t have to stop your medication if you’re worried. But you do need to know what to watch for. If you’ve been on an SSRI and start feeling off—especially if you’re drinking more water than usual or noticing swelling in your ankles—it’s worth asking your doctor for a simple blood test. Sodium levels are checked in routine panels, and catching this early means you can adjust your fluid intake, tweak your meds, or switch to another antidepressant without major disruption.

What you’ll find below are real patient stories and clinical insights tied to this issue. You’ll see how people managed SSRI hyponatremia without quitting their treatment, how doctors adjust care plans, and what alternatives exist when sodium imbalance becomes a problem. This isn’t about scare tactics—it’s about giving you the facts so you can talk smarter with your provider and stay safe while getting the mental health support you need.