When you take lithium, a mood-stabilizing medication commonly prescribed for bipolar disorder. Also known as lithium carbonate, it works by balancing brain chemicals—but it has a very narrow safety window. Even small changes in your body’s fluid levels can push lithium into toxic territory. This is why dehydration, a condition where your body loses more fluids than it takes in is one of the most serious risks for people on lithium. It doesn’t matter if you’re sweating in the heat, skipping water all day, or getting sick with vomiting or diarrhea—any of these can spike lithium levels fast.
Kidney function, how well your kidneys filter waste and regulate fluid balance is key here. Lithium is cleared from your body almost entirely by your kidneys. When you’re dehydrated, your kidneys hold onto water—and lithium—instead of flushing it out. That’s when you start seeing symptoms like shaky hands, confusion, dizziness, nausea, or even seizures. These aren’t just side effects; they’re warning signs of lithium toxicity, a medical emergency caused by too much lithium in the bloodstream. Many people don’t realize how quickly this can happen. One hot day, a missed meal, or a bad stomach bug can be enough to trigger it.
You don’t need to avoid water or live in fear, but you do need to be smart. Drink regularly, even if you’re not thirsty. Watch for signs your body is low on fluids—dry mouth, dark urine, feeling lightheaded when standing up. Avoid diuretics like caffeine and alcohol, especially if you’re sweating or ill. If you’re sick, talk to your doctor before skipping your dose. Most importantly, get regular blood tests. Lithium levels should be checked often, especially after any illness, change in diet, or new medication. Your doctor might adjust your dose if you’re at higher risk. This isn’t about restriction—it’s about control. Knowing how dehydration affects lithium gives you power over your treatment. Below, you’ll find real cases and clear advice on how to protect yourself while staying on this essential medication.
Lithium is effective for bipolar disorder but dangerous if combined with NSAIDs, diuretics, or dehydration. Learn how common medications and everyday habits can trigger toxic levels-and what to do to stay safe.
