Thiazide Diuretics and Gout: What You Need to Know About Uric Acid Risks

Thiazide diuretics are one of the most common pills prescribed for high blood pressure

Millions of people take hydrochlorothiazide (HCTZ) every day. It’s cheap, effective, and has been around for over 60 years. But if you’ve ever had gout-or even just high uric acid-this drug can make things worse. And many doctors don’t warn patients about it until it’s too late.

Thiazide diuretics like HCTZ and chlorthalidone work by helping your kidneys flush out extra salt and water. That lowers blood pressure. But here’s the catch: while they’re removing sodium, they’re also holding onto uric acid. And that small change can trigger a painful gout flare.

How exactly do thiazides raise uric acid?

It’s not magic. It’s biology.

Your kidneys have special transporters that move uric acid in and out of urine. One of them, called OAT1, normally pushes uric acid out of your blood and into the urine. But when you take a thiazide, it jams into that same transporter like a key stuck in the wrong lock. Instead of uric acid being kicked out, it gets pushed back into your bloodstream.

Another transporter, OAT4, does the same thing on the other side of the kidney cell. Thiazides swap places with uric acid, trapping it inside the kidney and letting it leak back into your blood. Within just 3 to 7 days of starting the pill, your uric acid levels can jump by 6% to 21%. That’s enough to push some people over the edge into gout.

Who’s most at risk?

Not everyone who takes thiazides gets gout. But certain people are far more likely to.

• Men with uric acid levels above 7.0 mg/dL
• Women with levels above 6.0 mg/dL
• People who’ve had even one gout attack in the past
• Those with kidney disease or obesity
• People who drink alcohol regularly or eat a lot of red meat and seafood

Studies show that after 180 days on thiazides, your risk of needing gout medication jumps by 41%. That’s not small. It’s not rare. It’s predictable.

And here’s something many don’t realize: the first sign isn’t always pain. Often, it’s just a blood test showing uric acid creeping up. That’s your body screaming for help-before the big flare hits.

Is chlorthalidone worse than hydrochlorothiazide?

For years, doctors thought chlorthalidone was riskier. It’s stronger, lasts longer, and was assumed to affect uric acid more.

But a 2019 study compared the two head-to-head. And guess what? The risk of new-onset gout was nearly identical. Both drugs do the same thing: block uric acid clearance. The dose matters more than the name.

So if you’re on 25 mg of HCTZ, switching to 12.5 mg of chlorthalidone won’t help. You’re still getting the same uric acid burden. The key isn’t which pill you take-it’s whether you need it at all.

Gout from thiazides looks just like regular gout

There’s no special version of gout caused by diuretics. It’s the same searing pain in the big toe, the redness, the swelling, the inability to wear a sock. The same joint inflammation. The same blood tests showing uric acid over 6.8 mg/dL-the point where crystals start forming.

What’s different is the trigger. Instead of a beer night or a steak dinner, it’s your blood pressure pill. And that makes it easy to miss. Patients often don’t connect the dots until they’ve had three flares in six months-and their doctor finally asks, “Are you on a diuretic?”

What should you do if you’re on thiazides and have gout?

If you’ve had gout before, thiazide diuretics are not your best option. That’s not opinion. It’s in the guidelines from the American College of Cardiology and the European Society of Cardiology.

Here’s what to ask your doctor:

1. Can we check my uric acid level before starting or continuing this drug?
2. Is there a better blood pressure medicine for me?
3. Could I switch to losartan? It lowers blood pressure AND helps flush out uric acid.
4. What about calcium channel blockers like amlodipine? They don’t raise uric acid.
5. Is spironolactone an option? It’s a potassium-sparing diuretic that doesn’t affect uric acid.

Some people think, “But I need to lower my blood pressure.” True. But you don’t need to use a drug that makes your gout worse. There are alternatives that work just as well-and won’t trigger flares.

What if you can’t stop thiazides?

Sometimes, you’re on multiple blood pressure meds. Sometimes, thiazides are the only thing that brings your pressure down. If you must keep taking them, you need a plan.

First: monitor. Get your uric acid checked every 3 to 6 months. If it climbs above 7.0 mg/dL (or 6.0 for women), don’t wait for pain. Talk about lowering it before it turns into flares.

Second: lifestyle. Cut back on alcohol, especially beer. Reduce red meat, shellfish, and organ meats. Drink more water-aim for 2.5 liters a day. Losing even 5% of your body weight can drop uric acid by 1 to 2 mg/dL.

Third: if your uric acid stays high, consider allopurinol. Start low-100 mg daily. It doesn’t stop pain during a flare, but it prevents new ones. The European League Against Rheumatism recommends keeping uric acid below 6.0 mg/dL for people with gout. That’s the sweet spot where crystals dissolve.

Why aren’t more doctors talking about this?

Because thiazides are cheap. Because they work. Because hypertension is common. And because gout is seen as a “lifestyle disease”-not a drug side effect.

But the data doesn’t lie. A 2024 study of over 247,000 people found that 18.7% of those on thiazides ended up needing gout medication within two years. That’s nearly 1 in 5. Compare that to 14.2% on other blood pressure drugs.

And here’s the kicker: hypertension itself raises gout risk. So does high uric acid. That means the two conditions feed each other. Thiazides make it worse. And once you start taking gout meds, you’re stuck in a cycle-prescribing pills to fix pills.

What’s changing in 2026?

More doctors are waking up. A 2021 survey showed 78% of cardiologists now check uric acid before prescribing thiazides. That’s up from 52% in 2015.

There’s also new research. A phase II trial (NCT04892105) is testing a new diuretic that blocks sodium reabsorption without touching uric acid transporters. Results aren’t due until late 2025, but if it works, it could replace HCTZ for millions.

Until then, the message is clear: if you have gout-or even high uric acid-thiazide diuretics aren’t your friend. They’re a risk you can avoid.

Bottom line

Thiazide diuretics save lives by lowering blood pressure. But they can also trigger painful, disabling gout flares. The risk is real. The mechanism is understood. The alternatives exist.

Don’t assume your doctor knows your uric acid history. Don’t wait for your toe to turn red. Ask for a blood test. Ask about losartan. Ask about spironolactone. Your body will thank you.

High blood pressure doesn’t have to mean gout. You just need to choose the right tool for the job.