Serotonin Syndrome: Signs, Causes, and What to Do If You Suspect It

When your body gets too much serotonin, a natural chemical that helps regulate mood, sleep, and digestion. Also known as serotonin toxicity, it can turn from a mild annoyance into a life-threatening emergency in hours. This isn’t about feeling a little extra happy—it’s about your nervous system going into overdrive because of how drugs interact. You don’t need to be on a cocktail of medications to trigger it. Sometimes, just adding a new painkiller or herbal supplement to your routine is enough.

SSRIs, a common class of antidepressants like sertraline and fluoxetine are the usual suspects, but they’re not alone. MAOIs, older antidepressants still used for treatment-resistant depression, can be even riskier when mixed with other drugs. Even over-the-counter cough syrups with dextromethorphan, migraine meds like triptans, or supplements like St. John’s wort can push serotonin levels too high. The problem isn’t the dose of one drug—it’s the combination. Many people don’t realize their doctor didn’t check for interactions because they assumed all prescriptions are safe together.

The symptoms show up fast: shivering, sweating, rapid heartbeat, high blood pressure, muscle stiffness, confusion, or sudden agitation. In worse cases, you might lose coordination, have seizures, or slip into unconsciousness. If you’ve recently started or changed a medication and feel off in this way, don’t wait. Go to the ER. There’s no lab test that confirms serotonin syndrome—doctors diagnose it by matching your symptoms to your drug history. The faster you get help, the better your odds. Stopping the triggering drugs and getting supportive care can save your life.

What you’ll find here are real cases and clear explanations from people who’ve been through this. You’ll learn which drug combos are most dangerous, how to spot early warning signs before it’s too late, and what to tell your doctor so they take it seriously. We also cover what happens after an episode—how to rebuild your treatment plan safely, which meds to avoid going forward, and how to communicate risks to caregivers. This isn’t theoretical. These are the stories and facts that help people avoid another scare.