Risks of a gastroscopy

A gastroscopy is a very safe procedure and the risks of serious complications are small.

A gastroscopy that's being used to diagnose a condition (diagnostic gastroscopy) has less than a 1 in 1,000 chance of causing a serious complication.

Due to being more invasive, a gastroscopy that's used to treat a condition (therapeutic gastroscopy) has a higher risk. However, the risk is still relatively small at around 1 in 100.

Possible complications of a gastroscopy include:

  • adverse effects from sedation
  • bleeding
  • perforation (tearing)

These are discussed below.


Sedation is usually safe, but it can occasionally cause complications including:

  • feeling or being sick
  • a burning sensation at the site of the injection
  • small particles of food falling into the lungs and triggering an infection (aspiration pneumonia)
  • irregular heartbeat
  • breathing difficulties

Very rarely (about 1 in 25,000 cases), the complications from sedation can result in a stroke.


Sometimes, during a gastroscopy the endoscope can accidentally damage a blood vessel, causing it to bleed.

The site of the bleeding can usually be repaired using a further gastroscopy, in the same way that bleeding varices or an ulcer is repaired. A blood transfusion may also be required to replace lost blood.


During a gastroscopy, there's a small risk of the endoscope tearing the tissue inside your oesophagus, abdomen or chest.

The warning symptoms include:

  • neck pain
  • pain when swallowing
  • abdominal pain
  • high temperature
  • breathing difficulties

If the perforation isn't severe, it can usually be left to heal by itself. You may be given antibiotics to prevent an infection occurring at the site of the tear.

If the perforation is more serious (indicated by severe pain that doesn't respond to painkillers), surgery may be needed to repair it.

Useful Links