Ascites Management: How Sodium Restriction and Diuretics Really Work

Ascites Management: How Sodium Restriction and Diuretics Really Work
Wyn Davies 22 November 2025 0 Comments

When your liver is damaged - especially from cirrhosis - fluid starts building up in your belly. This isn’t just swelling. It’s ascites, a serious sign that your liver isn’t keeping up. About half of people with cirrhosis will develop it within 10 years. And once it shows up, your risk of complications like infection or kidney failure jumps dramatically. The good news? Most cases can be controlled with two simple, proven tools: cutting back on salt and taking diuretics. But here’s the twist - what you’ve been told about salt might be wrong.

Why Ascites Happens

Ascites doesn’t happen because you ate too much soup or salty chips. It’s a chain reaction inside your body. When the liver is scarred, blood can’t flow through it easily. That raises pressure in the portal vein - the main blood vessel feeding the liver. When that pressure hits 12 mmHg or more, fluid leaks out into the belly. But that’s only half the story.

Your kidneys start holding onto sodium and water like they’re running out of supply. Why? Because your body thinks your blood volume is low, even though you’re full of fluid. It’s a cruel trick. Your brain and kidneys go into survival mode, releasing hormones that tell your kidneys to hang on to every drop of salt and water. The result? Your belly swells. Your legs get heavy. You feel bloated, short of breath, and exhausted.

This isn’t just uncomfortable - it’s dangerous. About 1 in 3 people with ascites will get spontaneous bacterial peritonitis, a life-threatening infection in the belly fluid. Without treatment, half of these patients won’t live past two years. That’s why managing ascites isn’t optional. It’s urgent.

Sodium Restriction: Less Salt, But How Much?

For decades, the rule was simple: eat less than 2 grams of sodium a day. That’s about 5 grams of table salt - one teaspoon. Most guidelines - from the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) - still say that.

But here’s what no one talks about: very few people can stick to that. A 2021 study found less than 40% of patients actually follow a 2-gram sodium limit. Why? Because 75% of the sodium we eat doesn’t come from the salt shaker. It’s in bread, canned soup, deli meat, sauces, and even breakfast cereal. Trying to avoid all of it feels impossible.

And now, new research is shaking things up. Two randomized trials published between 2017 and 2022 found that patients who ate 5-6.5 grams of salt per day (about 2-2.5 grams of sodium) actually had better outcomes than those on strict restriction. Their ascites resolved faster. They needed fewer hospital visits for fluid drainage. And - surprisingly - their kidneys handled it better.

Why? Because cutting sodium too low can backfire. When your body senses extreme salt deprivation, it triggers even more stress hormones. Blood flow to your kidneys drops. That raises your risk of hepatorenal syndrome - a deadly kidney failure that happens in up to 35% of patients on ultra-low sodium diets, compared to 18% in those with moderate restriction.

So what’s the real target? Experts are split. Dr. Guadalupe Garcia-Tsao, lead author of the AASLD guidelines, still recommends under 2 grams. But Dr. Pere Gines, who led the 2022 study, says strict restriction may be harmful. Dr. Frederick Wong from the University of Toronto suggests a middle ground: aim for 5-6.5 grams of salt per day. That’s not “no salt.” It’s “no processed junk.”

Doctor and patient reviewing blood test as diuretic molecules pull fluid from kidneys in anime style.

Diuretics: The Real Workhorses

If sodium restriction is the background check, diuretics are the main treatment. They’re the drugs that actually pull fluid out of your body. And they work - if used right.

The first-line drug is spironolactone. It blocks the hormone aldosterone, which tells your kidneys to hold onto sodium. You start with 100 mg a day. If after 3 days you’re not losing weight, you bump it up - every 3 days - until you hit 400 mg. Most people need at least 200 mg daily to see results.

But spironolactone alone isn’t enough for everyone. That’s where furosemide comes in. It’s a loop diuretic that acts faster and harder. You start at 40 mg a day, maxing out at 160 mg. It’s usually combined with spironolactone in a 100:40 ratio. So if you’re on 200 mg of spironolactone, you’d take 80 mg of furosemide.

The goal? Lose no more than 0.5 kg (1 pound) per day if you don’t have swollen legs. If you do have leg swelling, you can aim for 1 kg per day. Go faster than that, and you risk kidney damage or electrolyte crashes.

And yes - you need to get your blood checked. Twice a week, at least in the first month. You’re watching for low sodium (hyponatremia), low potassium, and rising creatinine. If your sodium drops below 130, you might need to adjust fluids or reduce diuretics. If it’s below 120, that’s a medical emergency.

And don’t take NSAIDs like ibuprofen or naproxen. They can wreck your kidneys when you have cirrhosis. Same with ACE inhibitors and ARBs - they increase the risk of kidney failure by more than double.

When Diuretics Don’t Work

Five to ten percent of people with ascites don’t respond to maximum diuretic doses. That’s called refractory ascites. It’s serious. Survival drops to 50% within six months.

At this point, diuretics won’t help anymore. The next step is large-volume paracentesis - draining the fluid with a needle. It’s done in a clinic or hospital. You get about 5 liters removed at a time. But here’s the catch: you also need albumin. For every liter of fluid removed, you get 8 grams of human albumin infused. Otherwise, your blood pressure crashes and your kidneys shut down.

It’s not a cure - but it’s a lifeline. Many patients get drained every few weeks. Some need it monthly. It’s inconvenient. But it keeps them alive.

Vaptans - drugs like tolvaptan - are sometimes used. They help your body get rid of water without losing sodium. But they cost $5,000-$7,000 per course. And you can only use them for 30 days. They’re not worth it for most people.

Patient weighing themselves at dawn with healthy meal, fading swollen belly, glowing liver in background.

What You Can Do Today

You don’t need to become a nutritionist. But you do need to make a few changes:

  • Stop eating packaged snacks, canned soups, and processed meats.
  • Read labels. Look for “sodium” - aim for under 500 mg per meal.
  • Use herbs, lemon, vinegar, and garlic instead of salt.
  • Don’t add salt at the table - even a pinch adds up.
  • Take your diuretics exactly as prescribed. Don’t skip doses, even if you feel fine.
  • Weigh yourself every morning, before eating or drinking.
  • Call your doctor if you gain more than 1 kg (2 pounds) in 2 days.

And if your doctor pushes you to eat under 2 grams of sodium - ask why. Show them the 2022 study from Gut and Liver Journal. Ask if a moderate approach might be safer for you. This isn’t about rebellion. It’s about smart, personalized care.

The Big Picture

The old rules are being rewritten. Ascites management isn’t one-size-fits-all anymore. We used to think: less salt = better. Now we know: too little salt can hurt. The best approach? Combine moderate sodium control with the right diuretic dose - and monitor closely.

The debate isn’t over. The PROMETHEUS trial, set to finish in late 2025, will compare unrestricted versus restricted diets in thousands of patients. That study might finally tell us what works best.

Until then, focus on what you can control: avoid processed food, take your meds, track your weight, and talk to your doctor. Ascites is serious - but it’s manageable. And with the right plan, you can live well for years.