Diagnosing GvHD
You have further tests and investigations if you have symptoms of GvHD.
Confirming if you have GvHD
Your symptoms might suggest that you have GvHD but you still need to have tests to confirm this. Your doctor might take a sample (a biopsy) of the affected area.
You might need to see different specialists for some of these tests. For example, if you have skin GvHD your doctor may refer you to a skin specialist (dermatologist).
Having a biopsy
The doctor removes a small sample of tissue from the affected part of your body. They send the sample to the lab so that a specialist doctor (pathologist) can examine it under a microscope. It may take a while to get the results of your biopsy.
The biopsy you have depends on which part of your body is involved. For example, you might need a skin biopsy or a liver biopsy.
Skin biopsy
The doctor gives you a local anaesthetic injection to numb your skin. Then they remove a small sample of the affected skin and put a dressing over the biopsy site.
Liver biopsy
You usually have an 
or at the same time as a liver biopsy. The doctor uses the images from the CT or ultrasound scan to guide the biopsy needle into the right place in the liver.
After giving you some local anaesthetic, the doctor puts a needle through your skin and into the affected part of the liver. The doctor takes tissue samples.
After a liver biopsy, you have to stay in hospital for a few hours or possibly overnight. The liver has a very rich blood supply and there is a risk of bleeding afterwards, so your nurse will monitor you closely.
Endoscopy
You might need an endoscopy if your doctor suspects you have GvHD in your . The doctor can take a biopsy during the .
To have this test the doctor uses a tube to look at the inside of your food pipe (oesophagus) and stomach.
Or you might need a tube into your back passage to look at your bowel (sigmoidoscopy or colonoscopy).
X-rays and scans
You may need an x-ray or CT scan of your lungs. This is painless and you don’t need any preparation for it.
Or you might have an ultrasound scan of your liver to see if there are any signs of GvHD.
Lung function tests
If you have symptoms of GvHD in the lungs, you have tests to check how well your lungs are working.
There are different types of lung function tests. They measure how well your lungs take in oxygen. And check how much air you breath in and out and how quickly.
