Acid Reflux Explained: Causes, Symptoms, GORD & Treatment

What Is Acid Reflux?

Acid reflux is a very common condition in the UK. It occurs when some of the acid content of your stomach travels backwards — up into your oesophagus (food pipe). This backflow of acid causes irritation and inflammation, producing the familiar burning sensation most people call heartburn.

Occasional acid reflux affects most people at some point. It becomes a clinical concern — and is diagnosed as gastro-oesophageal reflux disease (GORD) — when it happens frequently enough to cause troublesome symptoms or damage to the oesophageal lining.

How Does Acid Reflux Happen?

To understand acid reflux, you need to know about the lower oesophageal sphincter (LOS) — a ring of muscle that sits at the junction between your food pipe and your stomach. In normal function, the LOS closes tightly after food passes through, preventing stomach contents from travelling back upwards.

When the LOS weakens, relaxes at the wrong time, or fails to close properly, stomach acid — a powerful hydrochloric acid your body uses for digestion — can escape into the oesophagus. Unlike the stomach, the oesophageal lining has no protective mucus layer, so acid causes immediate irritation and, over time, inflammation and damage.

The medical term for this process is gastroesophageal reflux. The word “reflux” literally means “to flow back.” When this reflux is persistent and symptomatic, the condition is called GORD.

Symptoms of Acid Reflux and GORD

Acid reflux can produce a wide range of symptoms. They tend to be worse after eating, when lying down, or when bending forward. Mild acid reflux may cause only occasional discomfort; moderate to severe GORD can significantly affect quality of life.

Common symptoms

• Heartburn — a burning sensation in the chest or upper abdomen, often rising towards the throat
• Regurgitation — a sour or bitter taste in the mouth, or the sensation of acid or food rising into the throat
• Dyspepsia — discomfort, fullness, or pain in the upper abdomen; may also cause nausea and bloating
• Difficulty swallowing (dysphagia) — a feeling of food sticking or the sensation of a lump in the throat
• Persistent dry cough — caused by acid irritating the upper airways (see below)
• Hoarseness or a sore throat — particularly in the mornings, due to overnight acid exposure
• Excessive belching or bloating

How severe can symptoms be?

Symptoms range from mildly irritating — occasional heartburn after a large meal — to debilitating. Severe GORD can disrupt sleep, impair eating, and lead to significant anxiety around food. Left untreated, it can also cause lasting damage to the oesophageal lining and, in some cases, increase the risk of oesophageal complications.

Is Acid Reflux the Same as Heartburn?

These two terms are often used interchangeably, but they are not the same thing. Acid reflux is the physical process — the backflow of stomach acid into the oesophagus. Heartburn is one of the symptoms that acid reflux causes — specifically, the burning sensation felt in the chest or throat.

You can have acid reflux without experiencing heartburn (as in silent reflux), and heartburn-like symptoms can occasionally have other causes. If you are unsure whether your symptoms are due to acid reflux, a clinical assessment is the best way to find out. Read our full article on heart attack vs heartburn to understand when chest pain should be treated as an emergency.

Causes and Triggers of Acid Reflux

Acid reflux has both structural causes (factors that directly weaken the lower oesophageal sphincter) and lifestyle triggers that temporarily worsen reflux. Understanding your personal triggers is an important part of managing the condition.

Structural and medical causes

• Hiatus hernia — part of the stomach pushes up through the diaphragm, making reflux more likely
• Pregnancy — increased abdominal pressure and hormonal changes relax the LOS
• Obesity — excess abdominal fat increases pressure on the stomach
• Certain medicines — NSAIDs (ibuprofen, aspirin), calcium channel blockers, nitrates, and some antidepressants can worsen reflux
• Connective tissue disorders — conditions such as scleroderma affect oesophageal motility

Common lifestyle triggers

Complications of Untreated GORD

Most people with occasional acid reflux will not develop serious complications. However, persistent, untreated GORD can lead to significant problems over time.

Oesophagitis

Repeated exposure to stomach acid inflames and damages the oesophageal lining — a condition called reflux oesophagitis. In mild cases, this causes ongoing discomfort; in severe cases, it can lead to bleeding or ulceration.

Peptic ulcers

Persistent acid exposure can erode the lining of the oesophagus or stomach, forming ulcers. These may cause significant pain and can occasionally bleed. Read our detailed guide on peptic ulcers and PPI treatment for more information.

Oesophageal stricture

Scarring caused by repeated inflammation can narrow the oesophagus over time, making swallowing progressively more difficult — a condition called oesophageal stricture.

Barrett’s oesophagus

In some people, long-term acid exposure causes the cells lining the lower oesophagus to change — a condition called Barrett’s oesophagus. It does not usually cause additional symptoms, but it does increase the risk of oesophageal adenocarcinoma (a type of oesophageal cancer) and requires regular endoscopic monitoring.

Lifestyle Changes That Help Acid Reflux

NICE guidelines recommend lifestyle modification as the first approach for mild acid reflux. Many people achieve significant improvement without medication, particularly if they can identify and address their personal triggers.

• Eat smaller, more frequent meals rather than large portions
• Avoid eating within 2–3 hours of going to bed
• Raise the head of your bed by 15–20 cm (use bed risers or a firm wedge pillow — not extra pillows)
• Reduce or eliminate alcohol and smoking
• Cut back on coffee, carbonated drinks, and known food triggers
• Lose weight if you are overweight — even a modest reduction in BMI significantly reduces reflux frequency
• Wear loose-fitting clothing that does not constrict the abdomen
• Avoid lying down or exercising vigorously immediately after eating

Medical Treatment Options for Acid Reflux

When lifestyle changes are insufficient, several medical treatments are available. The choice depends on the severity of your symptoms, the underlying cause, and your medical history.

Antacids

Antacids (such as Gaviscon, Rennies, or Maalox) neutralise stomach acid and provide rapid, short-term relief. They are suitable for occasional heartburn but are not effective enough for frequent or severe GORD. Alginates such as Gaviscon also form a protective raft on top of stomach contents, reducing regurgitation.

H2 receptor antagonists (H2 blockers)

H2 blockers (such as famotidine) reduce acid production by blocking histamine receptors in the stomach lining. They are more effective than antacids for moderate symptoms and can provide overnight acid suppression. However, they are generally less potent than PPIs.

Proton pump inhibitors (PPIs)

PPIs — including omeprazole, lansoprazole, and esomeprazole — are the most effective medicines for GORD. They work by blocking the proton pumps in gastric parietal cells that are responsible for producing acid, resulting in sustained, powerful acid suppression. For most people with GORD, a PPI is the treatment of choice.

Low-dose PPIs are available over the counter for short-term use. Prescription-strength doses, or use beyond two weeks, require assessment by a qualified prescriber. Access Doctor’s regulated prescribers can assess your symptoms online and issue a prescription where appropriate. Learn more about how PPIs work.

Surgical and endoscopic treatment

For a small number of people whose GORD does not respond adequately to medication — or who wish to avoid long-term PPI use — surgical options are available. The most common procedure is laparoscopic fundoplication, in which the upper portion of the stomach is wrapped around the lower oesophagus to reinforce the LOS. This is a secondary care decision and requires specialist gastroenterological assessment.

When to Seek Urgent Help

Speak to a doctor urgently (same day or within days) if you have any of the following:

• Difficulty swallowing or the sensation that food is sticking
• Unexplained weight loss
• Persistent vomiting or vomiting blood
• Black, tarry, or bloody stools (signs of gastrointestinal bleeding)
• Symptoms that do not improve after two weeks of over-the-counter treatment
• New or worsening symptoms if you are over the age of 55