First Lady Michelle Obama shares tips on parenting with moms and other audience members in a WebMD Town Hall meeting in Miami, Florida.
Information and Resources
Liver Function Tests
Liver function tests (LFTs) are a group of blood tests that detect inflammation and damage to the liver. They can also check how well the liver is working. Liver function testing includes ALT, AST, alkaline phosphatase, PT, INR, albumin, and bilirubin.
Why Check Liver Function?
Most often, a liver function test panel is ordered as a routine lab test. Many doctors check liver function in new patients or during annual physicals.
Your doctor may conduct an LFT if:
- You are taking a medication that can harm the liver.
- You have liver disease.
- You have symptoms of liver or bile system disease (abdominal pain, nausea and vomiting, or yellow skin).
- You drink alcohol excessively.
Liver function tests may be done together in a panel or tested separately.
Liver Function Tests: ALT and AST
The liver filters and processes blood as it circulates through the body. It metabolizes nutrients, detoxifies harmful substances, makes blood clotting proteins, and performs many other vital functions. The cells in the liver contain proteins called enzymes that drive these chemical reactions.
When liver cells are damaged or destroyed, the enzymes in the cells leak out into the blood, where they can be measured by blood tests. Liver function tests check the blood for two main liver enzymes:
- Aspartate aminotransferase (AST), sometimes called SGOT. The AST enzyme is also found in muscles and many other tissues besides the liver.
- Alanine aminotransferase (ALT), sometimes called SGPT. ALT is almost exclusively found in the liver.
If ALT and AST are found together in elevated amounts in the blood, liver damage is most likely present.
Liver Function Tests: Alkaline Phosphatase, 5’ Nucleotidase, and GGT
Another of the liver's key functions is the production of bile, which helps digest fat. Bile flows through the liver in a system of small tubes (ducts), and is eventually stored in the gallbladder, under the liver.
When bile flow is slow or blocked, blood levels of certain liver enzymes rise:
- Alkaline phosphatase
- 5' nucleotidase
- Gamma-glutamyl transpeptidase (GGT)
Liver function tests may check for any or all of these enzymes in the blood. Alkaline phosphatase is by far the most commonly tested of the three.
If alkaline phosphatase and/or 5' nucleotidase and GGT are elevated, a problem with bile flow is most likely present. Bile flow problems can be due to a problem in the liver, the gallbladder, or the tubes connecting them.
WebMD Medical Reference
Top 12 Health Topics-
1.
-
2.
-
3.
-
4.
-
5.
-
6.
-
7.
-
8.
-
9.
-
10.
-
11.
-
12.
Top 12 Videos-
1.
-
2.
-
3.
-
4.
-
5.
-
6.
-
7.
-
8.
-
9.
-
10.
-
11.
-
12.
Hot Topics
- Which Drugstore Tooth Whiteners Work Best?
- Kids' Top 6 Worries and How to Fix Them
- Surprising Headache Triggers
- Safe Ways to Lose Weight Fast
- Counting Carbs When You Use Insulin
- Fibromyalgia: Symptoms and Treatments
- CML: How It Affects Your Body
- 6 Sex Mistakes Men Make
- Dupuytren's Contracture: What You Need to Know
- Symptoms of Vitamin B12 Deficiency
WebMD Video: Now Playing
FROM CBS NEWS
Third of malaria meds from Asia, Africa are fake
Almost half of malaria medications in southeast Asia and over a third from sub-Saharan Africa were packaged poorly, including some expired drugs that had been repackaged
More from CBS News:
Health Solutions From Our Sponsors
Advertise With Us|WebMD Corporate|Medscape Reference|eMedicineHealth|RxList|Medscape|MedicineNet|BootsWebMD
©2005-2012 WebMD, LLC. All rights reserved.
WebMD does not provide medical advice, diagnosis or treatment. See additional information.