Reflux and heartburn: too much stomach acid, or too little?

The short answer

Heartburn happens when stomach acid travels up into the food pipe (oesophagus), where it doesn’t belong. The problem is usually acid in the wrong place, not always too much acid. Pressure on the stomach, a weak valve, slow emptying, food triggers and stress all play a part. Acid-lowering medicine helps many people, and finding the reason it is happening matters too.

Reflux is one of the most common reasons people come to me with a long-term prescription they would like to understand better. Many have been on acid-lowering tablets for years, and are wondering whether that’s the whole story.

What is acid reflux?

Heartburn is a burning feeling in the chest caused by stomach acid travelling up towards the throat. When this keeps happening, it may be called gastro-oesophageal reflux disease (GORD) (NHS). Symptoms can include:

a burning feeling in the middle of the chest
a sour taste in the mouth
a recurring cough or hiccups
a hoarse voice
bad breath
bloating and feeling sick

Symptoms are often worse after eating, when lying down or when bending over (NHS).

Is reflux caused by too much stomach acid?

Not always. Your stomach is designed to be very acidic. It needs that acid to break down protein, absorb nutrients such as B12 and iron, and kill unwanted microbes. The oesophagus has no such protection, so even a normal amount of acid hurts when it gets there.

Reflux is more about the barrier than the amount of acid. The valve at the bottom of the oesophagus (the lower oesophageal sphincter) should stay shut except when you swallow. Things that weaken it or push contents upward include:

extra pressure on the tummy, from weight around the middle, pregnancy or tight clothing
large meals, and eating late at night
slow stomach emptying
a hiatus hernia
smoking and alcohol
certain foods, such as fatty meals, chocolate, coffee and spicy food, which affect some people
stress, which changes how the gut moves and how sensitive it is

What about low stomach acid?

In functional medicine, we also think about people whose stomach makes too little acid. This is more common with age and with long-term acid-lowering medicine, and in some people it’s linked with bloating, early fullness and poor absorption of certain nutrients. The research here is still developing, so I’m careful with it. I don’t use home “tests” such as the bicarbonate test, and I never suggest acid supplements to someone who has, or might have, an ulcer or gastritis.

Should you stop your reflux medication?

Please don’t stop prescribed medicine without speaking to your GP or prescriber (NHS). Stopping Proton pump inhibitors (PPIs) such as omeprazole and lansoprazole abruptly can cause rebound symptoms. Also, PPIs are sometimes essential, for example after bleeding, with Barrett’s oesophagus or with severe inflammation.

The NHS says a GP will usually prescribe a PPI for 4 or 8 weeks, depending on how serious the reflux is (NHS). We now know that long-term PPI use is linked to multiple health conditions, so if you’ve been on one for much longer and want to review it, that’s a conversation to have with your GP. I can work alongside them, supporting the gut while any change is made gradually.

How does functional medicine approach reflux?

I look for why the barrier is struggling, and work on several areas at once:

What we look at	Why it matters
Meal size, timing and how you eat	Smaller meals and not eating within 3 to 4 hours of bed reduce pressure (NHS)
Food triggers	Personal triggers vary, so we identify yours rather than cutting everything
Weight and waistline	Less pressure on the stomach means less reflux
Gut bacteria and bloating	Gas and small intestinal bacterial overgrowth (SIBO) can push contents upward
Stress and the nervous system	Calming the “fight or flight” response helps digestion
Sleep position	Raising the head of the bed by 10 to 20cm can help, but extra pillows don’t (NHS)
Nutrients	Long-term acid suppression can affect some nutrient levels, so we may check them

Soothing foods and herbs can help, as can testing for SIBO when bloating is a big part of the picture.

When should you see a GP?

The NHS advises seeing a GP if:

Please see your GP promptly if you’re over 55 with new symptoms, are vomiting blood or have black stools. If you have chest pain that spreads to your arm, neck, jaw or back, or comes with breathlessness, sweating or sickness, call 999. It could be your heart, not reflux.

Common questions

Is heartburn caused by too much acid?

Usually it’s caused by acid being in the wrong place. A weak valve, pressure on the stomach or slow emptying lets normal stomach acid reach the oesophagus, which isn’t built to cope with it.

How long can you take omeprazole?

The NHS advises that PPIs are usually prescribed for 4–8 weeks, although some people need longer-term treatment. Long-term use has been linked to low magnesium, vitamin B12 deficiency, gut infections, cognitive decline and an increased risk of fractures, so they should only be continued when there is a clear medical need, at the lowest effective dose, with regular review. Discuss your treatment with your GP and don’t stop without advice, as stopping suddenly can cause rebound acid symptoms.

What is the best sleeping position for reflux?

Raising the head of your bed by 10 to 20cm can help. Extra pillows can make it worse, because they bend you at the waist. Some people also find lying on their left side helps.

Can stress cause reflux?

Stress doesn’t create acid out of nowhere. It does change how the gut moves and how sensitive the oesophagus is, so many people notice their reflux is worse during stressful times.

If reflux is wearing you down, book a free discovery call and we’ll look at what’s driving it.