🚨 Seek urgent medical help for sudden breathlessness, breathlessness at rest, or waking at night gasping for air. Also seek urgent help for a rapid weight gain of roughly 2 kg or more over two to three days, or for new confusion, fainting or chest pain. These indicate fluid building up fast or the heart decompensating, and both are treated far more easily early than late. Never stop or reduce a diuretic, or any other heart medicine, on your own, however well you feel.

Definition

What Is Heart Failure?

Not the heart stopping, and not a single disease. It is a syndrome in which the heart either cannot fill properly or cannot pump strongly enough, so blood backs up and tissues receive less than they need.

The backing up is what produces the symptoms people notice: fluid in the lungs causing breathlessness, fluid in the legs causing swelling, and fluid in the abdomen causing bloating and early fullness at meals. The reduced forward flow produces the fatigue.

Nutrition matters here in three specific ways, and they are more particular than general healthy eating. Sodium and fluid affect how much volume the circulation has to carry. Certain nutrients are lost through the very diuretics used to treat it. And appetite frequently falls just when the body needs more, which is why unintended weight loss in heart failure is a serious finding rather than a good one.

💡 Key Insight: The most useful thing most people with heart failure can do at home is not dietary at all. It is weighing yourself at the same time each morning and telling your clinician when the number climbs quickly, because that rise is fluid, and it is the earliest signal available.

Anatomical illustration of a heart with enlarged chambers, showing fluid backing up into the lungs and pooling in the legs and abdomen

🧂 The sodium trial surprised people

SODIUM-HF randomised over 800 patients to a low-sodium target or usual care. It did not reduce hospital admissions, emergency visits or deaths, though quality of life and symptoms improved modestly¹.

⚖️ Weight loss is a red flag here

Unintended loss of weight and muscle, called cardiac cachexia, is associated with worse outcomes. In heart failure the goal is usually to protect weight and muscle, which reverses the advice given almost everywhere else.

💊 Diuretics remove nutrients too

Thiamine deficiency was found in a meaningful share of stable heart failure outpatients on standard therapy². Loop diuretics increase its loss in urine, which is a treatable and easily missed problem.

Signs & Symptoms

How Heart Failure Presents

Mostly as breathlessness, swelling and fatigue. The pattern of when they happen is what distinguishes it.

Feature	What it looks like	Worth knowing
Breathlessness on exertion	Doing less than before without stopping	Often attributed to age or being unfit, and so presented late
Breathlessness lying flat	Needing more pillows, or sleeping upright	Fairly specific for fluid, and a useful thing to report by number of pillows
Waking at night gasping	Suddenly, one to two hours after falling asleep	Report this promptly. It suggests fluid redistributing when lying down
Swollen ankles, legs or abdomen	Worse by evening, better after a night lying flat	Shoes and rings becoming tight is often noticed first
Rapid weight gain	Roughly 2 kg or more in two to three days	This is fluid, not fat, and it is the earliest actionable signal. Weigh daily
Fatigue and reduced exercise tolerance	Everything takes longer and costs more	Frequently the most limiting symptom, and the least visible
Early fullness, nausea, poor appetite	Eating little and losing weight without trying	Fluid in the abdomen and gut congestion. A reason to see a clinician, not to diet
Reduced urine output, or new confusion	Particularly in older adults	Can indicate worsening kidney perfusion; seek advice promptly

⚠️ Heart failure and kidney function are tied together, and that shapes the whole nutrition plan. Reduced kidney function changes how much potassium, phosphate, protein and fluid are safe, and several heart failure medicines raise potassium. This is why potassium-rich foods and salt substitutes cannot be recommended generically on this page. See chronic kidney disease.

Assessment

How Heart Failure Is Assessed

Diagnosis is one thing. What matters for nutrition is which type it is, how the kidneys are, and what the diuretics are doing.

Measure	What it tells you	What it misses
Echocardiogram	How the heart fills and empties, and which type of heart failure it is	A single snapshot; function varies with fluid status
Natriuretic peptide blood test	Whether breathlessness is likely to be cardiac	Affected by kidney function, age, weight and rhythm
Daily weight at home	Fluid accumulating, days before symptoms appear	Only works if done consistently, same time, same clothing
Kidney function and electrolytes	What is safe regarding potassium, fluid and protein	Changes with diuretic dose, so it needs repeating rather than assuming
Iron studies including ferritin and transferrin saturation	Iron deficiency, which is common in heart failure and worth treating even without anaemia	Ferritin rises with inflammation, so it can look falsely reassuring; see iron deficiency anaemia
Thiamine status, where diuretic use is long-standing	A correctable deficiency that loop diuretics promote²	Rarely tested unless someone asks
Sleep assessment	Sleep apnea, which is common in heart failure and treatable	See sleep apnea
Weight trend over months	Cachexia, the loss of weight and muscle that predicts worse outcomes	Easily hidden by fluid gain masking muscle loss on the scale

💡 Ask specifically about iron. Iron deficiency is common in heart failure, contributes to fatigue and breathlessness, and is treatable. It is assessed differently here than elsewhere, because inflammation raises ferritin and can make deficiency look absent. It is worth asking whether your transferrin saturation has been checked, not just your haemoglobin.

Treatment Comparison

Holistic vs. Conventional Treatment for Heart Failure

🌿 HOLISTIC

💊 CONVENTIONAL

🌿

Holistic / Functional Approach

Daily weights, moderate sodium, protecting muscle, and treating what is deficient

Highest-Value Habit

Daily morning weights, which detect fluid accumulating before symptoms do

Sodium

Moderation for symptoms and quality of life, which is what SODIUM-HF actually showed, rather than for survival¹

Protein and Muscle

Protected deliberately. Unintended weight loss here is a poor prognostic sign, not a success

Limitation, stated plainly

No dietary measure substitutes for the medicines that reduce mortality in heart failure

Full Holistic Approach Includes

Weighing daily, at the same time, and reporting a rapid rise rather than waiting for breathlessness.
Moderating sodium, mostly by reducing processed food rather than by removing the salt cellar.
Following the fluid advice you were actually given, since restriction is individual and not universal.
Enough protein and energy to protect muscle, in small frequent meals if fullness limits intake.
Treating iron deficiency where present, which improves symptoms.
Limiting alcohol, which weakens heart muscle directly and is a cause of heart failure in its own right.
Physical activity and cardiac rehabilitation, which improve capacity and quality of life.

🌿 Worth knowing: nutrition here is about symptoms, muscle and avoiding deficiency. The survival benefit in heart failure comes from the medicines, and that is not a close call.

💊

Conventional / Medical Approach

Medicines that prolong life, diuretics for symptoms, devices where indicated

Disease-Modifying

Several medicine classes reduce hospital admission and death in reduced ejection fraction, used together and titrated up

Diuretics

Control fluid and symptoms. They do not themselves prolong life, and doses are adjusted rather than fixed

Devices and Procedures

For selected people, alongside medication rather than instead of it

Alongside Either

Treating iron deficiency, sleep apnea, rhythm problems, and reviewing medicines that worsen fluid retention

Conventional Approach

Taking the disease-modifying medicines as prescribed, and at the dose reached by titration. This page names no specific drug, because the combination is a clinical decision.
Never stopping a diuretic or heart medicine independently, including when you feel well, which is when they are working.
Reporting rapid weight gain so the diuretic can be adjusted early.
Regular kidney function and potassium monitoring, since several of these medicines affect both.
Reviewing medicines that worsen heart failure, including some anti-inflammatory painkillers, with your prescriber.

⚠️ The result this page is built around, and it is not what most heart failure diet sheets say. SODIUM-HF randomised 806 patients across six countries to a dietary sodium target below 100 mmol a day or to usual care. Over 12 months there was no significant difference in the combined endpoint of cardiovascular admission, emergency visit or death. Symptoms and quality of life improved modestly¹. The honest reading is that sodium moderation is worth doing for how you feel, and severe restriction has not been shown to keep people alive or out of hospital.

Nutritional Strategy

Diet for Heart Failure

More individual than almost any other page on this site, because kidney function and diuretic dose change what is safe.

⚠️ Follow the fluid and potassium advice your own clinician gave you, not a general rule from a website. Fluid restriction is appropriate for some people with heart failure and unnecessary or harmful for others. Potassium is beneficial in some and dangerous in others, depending on kidney function and which medicines you take. Low-sodium salt substitutes are usually potassium chloride, and can cause dangerously high potassium in people on common heart failure medicines or with reduced kidney function³. This is the one page on this site where generic advice is genuinely unsafe.

Change	Why	Practical note
Weigh daily	Detects fluid before symptoms	Same time, after the toilet, before breakfast. Report a rise of about 2 kg over two to three days
Moderate sodium	Symptoms and quality of life¹	Mostly processed foods, bread, sauces and takeaways rather than the salt cellar. Not severe restriction
Protein and energy	Protecting muscle, because losing it predicts worse outcomes	Small frequent meals if early fullness limits intake. Do not diet unless a clinician has said to
Fluid	Individual to you	Ask what your limit is, if any. Do not adopt one from the internet
Alcohol	Directly toxic to heart muscle	A cause of heart failure in its own right. Where that is the cause, stopping can improve function substantially
Iron-containing foods, plus treatment if deficient	Iron deficiency is common here and worsens symptoms	Food alone rarely corrects an established deficiency; see iron deficiency anaemia
Potassium-rich foods	Depends entirely on your kidney function and medicines	Beneficial for some, hazardous for others. Ask before increasing them
Liquorice, and some herbal products	Cause sodium and fluid retention	Whole liquorice raises blood pressure and lowers potassium⁴; avoid it here

💡 If you are losing weight without trying, say so. In most conditions on this site that would be neutral or welcome. In heart failure, unintended loss of weight and muscle is associated with worse outcomes, and the usual causes, poor appetite, early fullness from abdominal congestion, and the effort of eating while breathless, are all treatable once someone knows about them.

Supplement Protocol

Evidence-Based Supplements

A short list, and an unusually long set of interactions, because heart failure medicines are unforgiving.

🚨 Do not take potassium supplements or potassium-based salt substitutes unless your clinician has told you to. Several heart failure medicines raise potassium already, and reduced kidney function raises it further. High potassium can cause dangerous heart rhythm disturbances and often produces no warning symptoms first. This is the most likely serious harm on this page, and it is placed at the top for that reason. Tell your clinician about every supplement you take.

Supplement	What it is actually for	Typical range	Timing	Notes & cautions
Thiamine (vitamin B1)	Correcting a deficiency promoted by loop diuretics, which increase urinary thiamine loss. Deficiency was present in a meaningful share of stable heart failure outpatients on standard therapy².	Discuss with your clinician, particularly on long-term loop diuretic therapy	With food	Cheap, safe and easily missed. It is a correction of a drug-induced loss rather than a treatment for heart failure itself. Severe deficiency can itself cause a form of heart failure, which is why it is worth asking about.
Iron, only if deficient and as directed	Treating iron deficiency, which is common in heart failure and worsens fatigue and breathlessness.	Assessed and prescribed by your clinician; intravenous iron is often used here rather than tablets	As advised	Do not self-supplement iron. Deficiency is diagnosed differently in heart failure because inflammation raises ferritin. See iron deficiency anaemia.
Vitamin D3	Correcting a documented deficiency. Not a heart failure treatment.	Test 25-OH-D first and set a daily dose with your clinician	With a fat-containing meal	Correct a deficiency because it is a deficiency. Avoid large intermittent doses; see osteoporosis. Discuss first if your blood calcium is raised.
Omega-3 (EPA and DHA)	Food first, oily fish. Modest evidence in heart failure and not a substitute for anything.	Agree any supplement dose with your clinician	With a fat-containing meal	Tell your clinician if you take an anticoagulant or antiplatelet, which many people with heart failure do, and before any planned procedure.

🚨 What to avoid, specifically. Potassium supplements and potassium salt substitutes, unless prescribed. Whole liquorice, which causes sodium and fluid retention and lowers potassium. Hawthorn and other cardiac herbal preparations, which interact with heart medicines. High-dose vitamin E. Effervescent and soluble tablets of any kind, which frequently carry a substantial sodium load that nobody counts. Ephedra and stimulant-containing products. And any product promising to strengthen the heart, since none has been shown to reduce admissions or deaths the way the prescribed medicines do.

💡 Where the real leverage is. Taking the medicines at the doses reached by titration, weighing daily and reporting a rise early, moderating sodium enough to feel better, protecting muscle, and getting iron deficiency found and treated. Those five cover almost everything nutrition can contribute here.

References & Evidence Notes

Each numbered entry below is either a source you can follow or a note setting out what the evidence does and does not support. Both are numbered together so the markers in the text line up.

Last reviewed 3 September 2026. Supplement entries are cross-checked against the NIH National Center for Complementary and Integrative Health and the Linus Pauling Institute Micronutrient Information Center.⁵ This page is nutrition education, not medical advice, and it does not replace your doctor. Nutrition does not treat heart failure. The survival benefit comes from prescribed medicines, and nothing here is a reason to stop, reduce or delay them. Fluid and potassium advice in particular must come from the clinician who knows your kidney function and your prescriptions, because generic advice on those two is genuinely unsafe. What nutrition education can do is help you understand the evidence well enough to have a better conversation with the clinician who does treat you.

Ezekowitz JA, et al. Reduction of dietary sodium to less than 100 mmol in heart failure (SODIUM-HF): an international, open-label, randomised, controlled trial. Lancet. 2022;399(10333):1391–1400. PubMed 35381194. 806 patients across six countries; no significant difference in the composite of cardiovascular admission, emergency visit or all-cause death at 12 months, with modest improvement in symptoms and quality of life. Open-label, and the usual-care group also reduced sodium somewhat, which narrows the contrast. It is the largest randomised test of this question and the reason this page recommends moderation rather than severe restriction. ↩ ↩ ↩ ↩ ↩
Prevalence of thiamine deficiency in a stable heart failure outpatient cohort on standard loop diuretic therapy. Clin Nutr. 2016;35(6):1424–1429. PubMed 26923517. Thiamine deficiency was present in a meaningful proportion of stable outpatients receiving standard loop diuretic therapy. Loop diuretics increase urinary thiamine loss, which is the proposed mechanism. This establishes that the deficiency occurs, not that supplementing it improves heart failure outcomes. ↩ ↩ ↩
On potassium: several heart failure medicine classes reduce potassium excretion, and reduced kidney function compounds this. Potassium-based salt substitutes are a recognised route to hyperkalaemia in exactly this population, and high potassium can cause dangerous arrhythmia with little warning. See the NIH Office of Dietary Supplements potassium fact sheet, ods.od.nih.gov, and chronic kidney disease. ↩
On liquorice: glycyrrhizin causes sodium and water retention and potassium loss, raising blood pressure and worsening fluid overload, which is why whole liquorice is listed as one to avoid here. See the NIH National Center for Complementary and Integrative Health entry on liquorice root, nccih.nih.gov. ↩
NIH National Center for Complementary and Integrative Health, nccih.nih.gov, and the Linus Pauling Institute Micronutrient Information Center, lpi.oregonstate.edu. ↩