How does my doctor determine if I have NAFLD or NASH?
Because most people with NAFLD have no symptoms and screening for it is not recommended at this time, fatty liver disease is often discovered during a routine blood test or screening for another medical condition. For example, your blood work may show high levels of liver enzymes, or an ultrasound of your abdomen might reveal that your liver looks enlarged. Your doctor will use a variety of methods to determine if you have fatty liver disease.
These tests cannot show inflammation or fibrosis, so your doctor can’t use them to determine whether you have simple fatty liver or NASH. However, there are other types of imaging tests that are used to measure fibrosis by measuring the stiffness of your liver. Liver stiffness indicates scarring; the more scarring that is present the stiffer your liver is. The following tests can help your doctor determine if, and to what extent, you have fibrosis of the liver.
- Transient elastography
This test measures liver stiffness with a special ultrasound machine, the most common being FibroScan. Like a regular ultrasound, the exam is painless and non-invasive.
- Magnetic resonance elastography (MRE)
This is a newer, noninvasive test that combines features of ultrasound and MRI imaging to create a visual map showing gradients of stiffness throughout the liver. MRE has been shown to be a more reliable measure of liver stiffness in severely obese patients.
If your medical evaluation shows no alternative causes for liver disease (such as medications, viral hepatitis, or excessive use of alcohol) and imaging studies of your liver show fat and liver stiffness, NASH is suspected. If your doctor feels that further confirmation is needed to make a definitive diagnosis of NASH, a liver biopsy may be ordered.
During a biopsy, your doctor will insert a needle between your ribs into your liver to collect a small sample of liver tissue for laboratory testing. NASH is diagnosed when examination of the tissue with a microscope shows fat along with inflammation and damage to liver cells. If the tissue shows fat without inflammation and damage, simple fatty liver or NAFLD is diagnosed. You can read more detailed information about preparing for a liver biopsy here.
Please call our helpline at 1-800-GO-LIVER if you have questions after speaking with your healthcare professional.
Ask your doctor to explain all your test results and their implications, and don’t hesitate to ask questions. This will help you have a better understanding of your diagnosis and why your healthcare provider is recommending a particular course of treatment going forward.