Functional Heartburn: Understanding Symptoms and Treatment in the UK

Functional heartburn is a chronic digestive condition characterised by a burning sensation in the retrosternal area (behind the breastbone). While it feels identical to Gastro-oesophageal Reflux Disease (GORD), it is distinct because there is no evidence of increased acid exposure or injury to the lining of the oesophagus. In the UK, many patients find themselves frustrated after an endoscopy (a camera test) returns 'normal' results despite persistent symptoms.

According to NICE (National Institute for Health and Care Excellence), functional disorders are common and relate to how the nerves in the gut process signals. In functional heartburn, the nerves in the oesophagus may be overly sensitive, misinterpreting normal activity as pain or burning. This is often referred to as visceral hypersensitivity.

The primary symptom is a burning discomfort in the chest that may rise toward the throat. However, unlike standard acid reflux, functional heartburn typically has the following characteristics:

• Symptoms do not significantly improve with high-dose Proton Pump Inhibitors (PPIs) like omeprazole or lansoprazole.
• There is no sour or bitter taste in the mouth (acid regurgitation).
• Symptoms may be triggered by stress or anxiety rather than specific fatty foods.
• Diagnostic tests, such as pH monitoring and gastroscopy, show no abnormalities.

It is important to distinguish this from Oesophageal Hypersensitivity, where symptoms are triggered by normal amounts of reflux. In functional heartburn, the burning occurs even when there is no reflux event at all.

Medical research in the UK and globally points toward the gut-brain axis as a key factor. The oesophagus is lined with a complex network of nerves. In people with functional heartburn, these nerves may have a lower threshold for pain. Factors that contribute to this include:

• Stress and Anxiety: Psychological distress can heighten the perception of bodily sensations.
• Oesophageal Barrier Function: Microscopic changes in the tissue may allow irritants to reach nerve endings more easily.
• Central Sensitisation: The brain becomes highly efficient at 'feeling' pain in the chest area, even without a physical stimulus.

Impact of Lifestyle

While food is less of a direct cause than in GORD, habits that irritate the gut or increase stress can worsen the frequency of episodes. Lack of sleep and high caffeine intake are common contributors noted by British patients.

Because functional heartburn is not caused by acid, standard antacids often fail. Management focuses on desensitising the nerves. Options include:

• Neuromodulators: Low-dose medications such as amitriptyline are sometimes used. These are not used for depression in this context, but to 'turn down the volume' of the pain signals coming from the gut.
• Psychological Therapies: Cognitive Behavioural Therapy (CBT) or gut-directed hypnotherapy can be highly effective in managing the gut-brain connection.
• Lifestyle Adjustments: Stress management, regular exercise, and maintaining a healthy weight as per NHS guidance can reduce the burden of symptoms.
• Dietary Review: While not acid-driven, some patients find a low-FODMAP approach or reducing stimulants helps settle the digestive system.

If you are experiencing persistent chest pain or burning, it is vital to get a professional assessment to rule out other conditions. You should consider booking a consultation with an online GP if:

• Your symptoms are not responding to over-the-counter GORD treatments.
• You have been told your endoscopy results are normal but you are still in pain.
• You need advice on how to manage the psychological impact of chronic gut pain.
• You require a review of your current medications or a sick note for work due to symptom flare-ups.

An online doctor can review your history, discuss the Rome IV criteria (the international standard for diagnosing functional gut disorders), and suggest a management plan tailored to your needs.

Living with a functional disorder can be taxing because the symptoms are 'invisible' to standard medical tests. It is important to remember that the pain you feel is real, even if there is no physical damage. Engaging with support groups or psychological support can help manage the frustration that often accompanies these diagnoses. Following a consistent routine and practicing mindfulness are evidence-based ways to support your nervous system and digestive health over the long term.