Blood tests have many different uses. Some of these include being used to diagnose a condition, to monitor a particular organ in the body such as the kidney or liver, and they can also be used to give measurements of bodily processes such as blood sugar, or current levels of inflammation.
The liver function blood test is also known as LFT. It is one of the most commonly requested tests, and provides information on how the liver is functioning. It gives different markers of how healthy the liver tissue is, as well as other markers of liver function.
This would be a normal test to order when doing some routine blood tests. Specifically, it will give your doctor information on how your liver is functioning at that point in time. Your liver is involved in processing many medications, and so it may need to be tested at certain intervals to ensure the medications are not causing any signs of damage to the liver.
You do not need to be fasting for this blood test, there are no special requirements. It can be taken like any normal blood test and is usually taken in a gold or yellow colour bottle. Remember to press hard for a good few minutes after the needle has been removed, to present a nasty bruise!