When we eat, food passes down the oesophagus (gullet) into the stomach. Cells in the lining of the stomach make acid and other chemicals which help to digest food. Stomach cells also make mucus which protects them from damage from the acid. The cells lining the oesophagus are different and have little protection from acid.

There is a circular band of muscle (a 'sphincter') at the junction between the oesophagus and stomach. This relaxes to allow food down, but then normally tightens up and stops food and acid leaking back up (refluxing) into the oesophagus. In effect, the sphincter acts like a valve.

What are reflux and oesophagitis?

• Acid reflux is when some acid leaks up (refluxes) into the oesophagus.
• Oesophagitis means inflammation of the lining of the oesophagus. Most cases of oesophagitis are due to reflux of stomach acid which irritates the inside lining of the oesophagus.

The lining of the oesophagus can cope with a certain amount of acid. However, it is more sensitive to acid in some people. Therefore, some people develop symptoms with only a small amount of reflux. However, some people have a lot of reflux without developing oesophagitis or symptoms.

Gastro-oesophageal reflux disease (GORD)
This is a general term which describes the range of situations - acid reflux, with or without oesophagitis and symptoms.

What are the symptoms of acid reflux and oesophagitis?

• Heartburn is the main symptom. It is a burning feeling which rises from the upper abdomen or lower chest up towards the neck. (It is confusing as it has nothing to do with the heart!)
• Other common symptoms include: pain in the upper abdomen and chest, feeling sick, an acid taste in the mouth, bloating, belching, and a burning pain when you swallow hot drinks. Like heartburn, these symptoms tend to come and go, and tend to be worse after a meal.
• Some uncommon symptoms may occur. This makes the diagnosis difficult in some cases as the symptoms can mimic other conditions. For example:
  • A persistent cough, particularly at night. This is due to the refluxed acid irritating the windpipe. Hoarseness or asthma symptoms can sometimes be due to acid reflux.
  • Severe chest pain develops in some cases (and may be mistaken for a heart attack).

What causes acid reflux and who does it affect?

The sphincter at the bottom of the oesophagus normally prevents acid reflux. Problems occur if the sphincter does not work very well. This is common, but in most cases it is not known why it does not work so well. In some cases the pressure in the stomach rises higher than the sphincter can withstand. For example, during pregnancy, after a large meal, or when bending forward. If you have a hiatus hernia (when part of the stomach protrudes into the chest through the diaphragm), you are quite likely to develop reflux. (See separate leaflet called 'Hiatus Hernia'.)

Most people have heartburn at some time, perhaps after a large meal. However, about 1 in 3 adults have some heartburn every few days, and nearly 1 in 10 adults have heartburn at least once a day. In many cases it is mild and soon passes. However, it is quite common for symptoms to be frequent or severe enough to affect quality of life. Regular heartburn is more common in smokers, pregnant women, heavy drinkers, the overweight, and those aged between 35 and 64.医学全在线www.med126.com

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