Heartburn

Struggling with heartburn? Here’s what you need to know to find relief.

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What is heartburn?

Heartburn is a burning pain in your chest. This pain is caused by stomach acid rising from your stomach into your oesophagus (the pipe that takes food from your mouth to your stomach).

This can cause:

- Burning pain in the middle of your chest

- Pain which is worse when you bend over or lie down

- Burning pain that radiates into your back

By learning more about the causes of, tests for, and treatment for heartburn, you can understand it better and make informed decisions to get back on track.

Why does heartburn happen?

There are several possible causes of heartburn, and it’s important to find out what’s causing yours.

Here are the main causes of heartburn:

Gastroesophageal reflux disease (GORD)
Hiatus hernia, when part of your stomach moves up into your chest
Surgery you’ve had in the past (especially bariatric surgery)
Certain foods and drinks, such as alcohol, coffee, chocolate, and fatty or spicy foods
Being overweight
Smoking
Pregnancy
Stress or anxiety
Medication, such as anti-inflammatory painkillers
Overgrowth of bacteria in your small intestine (this is called SIBO)

Diagnosing heartburn

Diagnostic testing allows us to pinpoint the exact cause so we can recommend the right solution.

Oesophageal manometry, 24-hour pH, malabsorption breath tests, SIBO & gastric emptying

At the Functional Gut Clinic, we use the following highly accurate and trusted diagnostic tools, to identify the underlying cause of your heartburn:

Oesophageal manometry – which measures the function of your oesophagus (food pipe)

24-hour pH impedance monitoring – which looks at whether you have any reflux

Carbohydrate malabsorption breath test – which finds out if you have certain food intolerances (lactose or fructose)

Small intestinal bacterial overgrowth (SIBO) breath test – which finds out if you have an overgrowth of bacteria in your small intestine (called SIBO)

Gastric emptying test – which measures how quickly food leaves your stomach

Find out more and book your test

Learn more about heartburn

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Apple Cider Vinegar for Heartburn: Does the Evidence Hold Up?

Apple Cider Vinegar for Heartburn: Does It Actually Work?

Diet| News

May 31, 2026•4 min read

Listen to some experts, and apple cider vinegar gets recommended as a heartburn treatment — almost like a cure-all. At first glance, it doesn’t quite add up. Heartburn is caused by acid reflux, so adding something acidic into the mix seems like it would make things worse, not better.

The idea comes from the “low stomach acid” theory. It suggests the valve between the stomach and oesophagus only closes properly when acidity is high. By that logic, increasing stomach acid, for example with apple cider vinegar, should improve symptoms rather than reduce them.

But is this actually true? Does apple cider vinegar help with heartburn? Or is it another bit of useless “podcast wisdom”? Let’s find out.

What Causes Heartburn in the First Place?

Heartburn is caused by acid entering the oesophagus from the stomach. Usually, the lower oesophageal sphincter (LES) stops acid from backflowing. However, if it’s weakened or the pressure is too great, it can open, allowing acid in.

That’s the mainstream theory.

Why People Use Apple Cider Vinegar for Heartburn

The “Low Stomach Acid” Theory

Not everyone is convinced by the idea that the LES opens due to weakness or increased pressure in the stomach. While mainstream medicine acknowledges the role of factors like smoking, alcohol, and certain foods in opening the LES, other people argue it’s caused by too little acid in the stomach.

According to this theory, “low stomach acid” can mimic the symptoms of acid reflux. But the mechanism is different. A lack of stomach acid causes poor digestion. This creates gas bubbles that rise into the oesophagus, carrying stomach acid with them.

Where This Idea Falls Short

The “Low Stomach Acid” theory goes a step further. It argues that LES dysfunction occurs specifically because there’s not enough acid, and that only by increasing stomach acidity will the LES clamp shut properly.

However, there’s limited clinical evidence supporting ACV for reflux. Most cases of heartburn are caused by too much acid production (e.g., due to fatty foods) or because certain factors weaken the LES. It’s not usually a lack of acid.

What Does the Evidence Actually Say?

There really isn’t a lot of evidence.

Apple cider vinegar itself has numerous health benefits. But its effect on acid reflux hasn’t been fully investigated. A 2015 graduate thesis found that ACV may prevent heartburn. However, the sample size here was small.

In the case of low stomach acid, it may provide some benefits. However, it’s hard to diagnose low stomach acid from symptoms alone, so it may make things worse.

That being said, a lack of evidence is not proof that it works or doesn’t work.

Can ACV Make Heartburn Worse?

Yes. Introducing an acidic substance to an already acidic environment could exacerbate symptoms, especially if you’ve already got an overproduction of acid.

You may notice:

·Irritation in the oesophagus

·Worsening reflux symptoms

·Dental enamel damage/erosion

If you want to try using ACV, it’s best to start small. A teaspoon is enough to see if there’s a negative effect. You can always gradually increase the dose.

Are There Situations Where ACV Might Help?

In rare cases where genuine low stomach acid is involved, ACV might be a suitable treatment. But it’s only suitable for mild symptoms and should never be used as a primary treatment.

You’ll want to undergo testing first to rule out other potential causes of heartburn or chest pain. The Functional Gut Clinic offers acid reflux testing that measures the presence of acid in the oesophagus. They also offer testing for low stomach acid. Both could help narrow down the underlying cause of your symptoms.

Better-Established Ways to Manage Heartburn

Dietary Adjustments

Heartburn is often linked to diet. Eating trigger foods such as fatty foods, caffeine, alcohol, or late meals, can cause an episode of acid reflux. By reducing these triggers, you could see if your heartburn is due to high acid levels.

Lifestyle Changes

Just tweaking your lifestyle can reduce heartburn. Try these tips:

·Maintain a healthy weight — excess abdominal pressure can worsen reflux

·Elevate your head during sleep — helps prevent acid from travelling upward

·Avoid lying down straight after meals — wait at least 2–3 hours before resting

Medical Options

If heartburn persists, your doctor may prescribe medications. Antacids are the best option to relieve an immediate acid attack, while PPIs and H2 blockers can provide long-term acid suppression.

Get Your Heartburn Checked

Heartburn is common, but the cause isn’t always obvious. Treating the wrong cause can make things worse. If your symptoms keep coming back, it’s worth moving beyond trial and error.

The Functional Gut Clinic offers targeted testing for acid reflux and GERD to help identify what could be driving your symptoms. With a clearer diagnosis, you can follow a plan that’s tailored to you rather than relying on guesswork or trends.

Read the next interesting article: Chronic Cough from Reflux: When Your Cough Is Actually GORD

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Heartburn is a burning pain in your chest.

Heartburn is often experienced after eating and can last anywhere from a few minutes to several hours. The stomach releases more acid after eating certain foods, including spicy dishes, fatty foods, citrus fruits, tomato-based products, garlic, and caffeinated drinks. The more acid that is produced, the greater the risk of heartburn.

Other factors include obesity, smoking, stress, pregnancy, and eating too close to bedtime.

What are the symptoms of heartburn?

Heartburn primarily causes an uncomfortable or burning sensation in the middle of your chest. You may also experience:

A burning sensation in your throat
A strong acidic or sour taste in your mouth
Difficulty swallowing (dysphagia)
A feeling of pressure or pain behind your breastbone
Repeated coughing
Hoarse voice

In addition to these symptoms, the pain from the acid can get worse when lying down or bending over. This is because the acid flows out of the stomach and into the oesophagus. Whenever you lie down, you increase the risk of heartburn-related symptoms.

Constant heartburn is a sign of a severe underlying condition. Most people experience heartburn in episodic attacks – usually after consuming certain foods. If the heartburn is persistent, it’s crucial to speak to a medical professional. You can also consider organising a test via The Functional Gut Clinic (see below).

What causes heartburn?

Heartburn occurs when the contents of the stomach enter the oesophagus (the food pipe connecting your stomach to your throat). Usually, the stomach contents are prevented from going back into the oesophagus by a juncture called the lower oesophageal sphincter. However, in some people, this sphincter doesn’t function properly.

Heartburn is a symptom of gastroesophageal reflux disease (GORD). GORD simply refers to the backflow of acid from the stomach into the oesophagus. GORD is the condition; heartburn is the symptom.

Several factors increase the risk of heartburn. The causes of heartburn and GORD either increase acid production within the stomach or affect the functioning of the lower oesophageal sphincter. These include:

Hiatal hernia. A hiatus hernia involves a part of your upper stomach penetrating through the diaphragm (the layer of muscle separating your chest from your stomach). This usually occurs due to a weakness or tear.
Pregnancy. If you become pregnant, the increased pressure during the third trimester (and sometimes earlier) forces the stomach contents backwards, causing heartburn.
Surgery. Previous surgery, especially bariatric surgery, increases the risk of not only heartburn but also a hiatus hernia.
Smoking. Smoking is closely linked to heartburn and GORD. People who quit smoking notice a significant reduction in heartburn symptoms.

Overweight or obesity. Being overweight or obese is a major risk factor for GORD. This is likely due to the increased pressure in the stomach alongside a diet high in fatty, processed foods.
Medications. Certain medications, such as anti-inflammatory painkillers (e.g., ibuprofen or aspirin), sedatives, and blood pressure medications, can increase your risk of heartburn.
Stress or anxiety. An increase in stress or anxiety can increase acid production in some people, leading to heartburn. It’s often accompanied by another factor.
Small intestine bacterial overgrowth (SIBO). Excessive bacterial growth in the small intestine leads to increased abdominal pressure and subsequent acid reflux, which can cause heartburn. Managing SIBO often reduces these symptoms.

Foods to avoid

Acid production is a normal part of the stomach’s function. The acid helps digest food. Certain foods require more acid to digest, triggering an increased production in the stomach.

For most people, this isn’t an issue as the acid flows into the small intestine. However, if you struggle with heartburn and GORD, then it’s sensible to limit or avoid certain foods. These include:

Citrus fruits (like oranges and grapefruits)
Tomatoes and tomato-based products
Spicy foods
Garlic and onions
Chocolate
Mint
Fatty or fried foods
Caffeinated beverages (such as coffee and tea)
Carbonated drinks
Alcohol

It’s not just the food. Eating an excessively large meal, wearing tight clothes, and lying down soon after eating can increase the risk of heartburn. If you’re experiencing persistent heartburn, it’s often linked to diet rather than another factor.

Is heartburn the same as GORD?

No. Heartburn specifically refers to the burning sensation in the chest. GORD is the underlying condition involving the backflow of acid. Heartburn is a symptom of GORD. Acid reflux is sometimes used as shorthand for GORD – however, not every attack of acid reflux is an example of GORD.

Acid reflux refers to any episode of acid backflowing into the oesophagus. If the episodes occur two or more times a week, it is diagnostic for GORD. Most people experience acid reflux episodes occasionally. This can increase in frequency as acid reflux progresses to GORD. You should speak to a doctor if you notice this change.

Does acid reflux always cause heartburn?

Heartburn is always caused by the backflow of acid into the oesophagus. Several other conditions can create a similar sensation. For example:

Oesophageal ulcers. Ulcers occur due to erosion of the oesophageal lining. Often associated with acid reflux or overusing anti-inflammatory medications.
Oesophagitis. Severe inflammation of the oesophagus is closely linked to GORD. However, it can also be caused by medications and infections. An allergic condition known as eosinophilic oesophagitis can also cause heartburn.
Functional heartburn. Unlike the other conditions, this isn’t a problem with your oesophagus or stomach. It’s caused by a disorder of the gut-brain connection. It involves the same heartburn symptoms but without any signs of acid reflux or inflammation. It’s connected to overactive nerves.

How long does heartburn last?

Heartburn is not a permanent condition. It lasts as long as the acid is present to irritate the oesophagus and throat. Most people experience heartburn and GORD for between a few minutes to several hours. The timespan often depends on the underlying cause. For example, if your heartburn is due to your diet, it might go away within a few minutes. In contrast, if you have a hiatus hernia, the heartburn might persist for much longer, even after standing up.

Constant heartburn is a rare symptom. It’s a concerning sign, as the acid can continue to damage your oesophagus. If you’re constantly feeling heartburn (or using lots of antacids), then it’s critical to speak to a doctor.

Is heartburn serious?

Most cases of heartburn aren’t serious. It’s common to experience heartburn after a large meal or eating certain foods. However, if the heartburn becomes repeated or constant, it can cause long-term damage. Usually, the damage caused by acid reflux heals like any injury. If it happens regularly, then the oesophagus lining can become permanently injured.

Potential long-term complications include:

Oesophageal strictures. The lining of the oesophagus becomes replaced with scar tissue due to repeated inflammation. This scar tissue causes a narrowing of the oesophagus (stricture), which prevents food from getting through.
Intestinal metaplasia. The tissue lining of the oesophagus undergoes a change to look more like the lining of your intestines, protecting it from damage. It is called Barrett’s oesophagus and is a precancerous condition.
Oesophageal cancer. Cancer is a rare complication of GORD and heartburn. It occurs due to persistent inflammation and cellular changes. The longer your heartburn persists, the greater the risk of cancer.

Heartburn and GORD can also indicate problems in your stomach. For example, excess acid production can lead to gastritis (stomach inflammation) and stomach ulcers. It may also aggravate preexisting conditions such as asthma.

How do we diagnose the causes of heartburn?

The following tests may be used to diagnose what is causing your heartburn:

Oesophageal manometry – which measures the function of your oesophagus (food pipe)
24-hour pH impedance monitoring – which looks at whether you have any reflux
Carbohydrate malabsorption breath test – which finds out if you have certain food intolerances (lactose or fructose)
Small intestinal bacterial overgrowth (SIBO) breath test – which finds out if you have an overgrowth of bacteria in your small intestine (called SIBO)
Gastric emptying test – which measures how quickly food leaves your stomach
The following tests may be used to diagnose what is causing your heartburn:
Oesophageal manometry – which measures the function of your oesophagus (food pipe)
24-hour pH impedance monitoring – which looks at whether you have any reflux
Carbohydrate malabsorption breath test – which finds out if you have certain food intolerances (lactose or fructose)
Small intestinal bacterial overgrowth (SIBO) breath test – which finds out if you have an overgrowth of bacteria in your small intestine (called SIBO)
Gastric emptying test – which measures how quickly food leaves your stomach

Heartburn treatment

Lifestyle changes

Most people who experience occasional heartburn symptoms can benefit from lifestyle changes. This involves limiting exposure to potential triggers. You might want to try:

Avoiding trigger foods, such as fatty foods or caffeinated beverages
Eating smaller meals
Avoiding tight clothing
Avoiding lying down immediately after eating
Quitting smoking and alcohol consumption.

Often, people find that small changes to their diet can stop or reduce episodes of heartburn. If the heartburn continues, it’s usually a sign that something else is going on. It’s crucial to get to the bottom of your symptoms; otherwise, they will persist.

Medication

As heartburn is caused by acid, neutralising this acid relieves symptoms. The primary treatment for heartburn is an over-the-counter (OTC) antacid, such as Gaviscon or Alka-Seltzer. These medications provide immediate relief from your symptoms – perfect for tackling a sudden acid reflux attack. If you experience constant heartburn, it’s sensible to carry antacids with you. However, excessive use of antacids can cause other problems.

Your doctor may prescribe medications that prevent acid production. This includes:

Proton Pump Inhibitors (PPIs). These medications reduce stomach acid production by blocking the enzyme in the stomach lining that produces acid. Common examples include omeprazole, esomeprazole, and pantoprazole. PPIs are used to treat GORD by allowing the oesophagus to heal and preventing further damage.
H2 Receptor Antagonists. These drugs work by blocking H2 receptors on stomach cells that signal the production of acid. This results in decreased stomach acid output. Examples include ranitidine, famotidine, and cimetidine. They are effective in relieving GORD symptoms and are generally used for milder cases.

Surgery

In the majority of cases, lifestyle changes and medication are enough to prevent heartburn symptoms. If GORD doesn’t respond to medication, surgery might be a potential option. This can repair a hiatus hernia, strengthening the lower oesophageal sphincter and permanently preventing the backflow of acid.

Procedures include:

Nissen fundoplication. This procedure tightens the junction between the stomach and the oesophagus.
Transoral incisionless fundoplication. A similar procedure performed non-surgically using an endoscope.
LINX device. A tiny ring of magnets is placed around the junction between the stomach and oesophagus to prevent reflux. It’s a type of minimally invasive surgery.

When should you seek medical care for heartburn?

Heartburn is extremely uncomfortable. However, most cases are relatively mild and treatable with antacids. Speak to a medical professional if:

You experience heartburn more than once a week
You have other associated symptoms
You have difficulty swallowing
Your heartburn persists despite treatment
You’re over the age of 60
You have a tight or squeezing chest pain
You cough up blood

Remember, occasional heartburn is relatively normal. But if you have constant heartburn, it’s crucial to get tested. The Functional Gut Clinic is highly experienced in diagnosing acid reflux. We’ll organise your test and provide advice on what to do next.

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