A TIBC, or transferrin, test is used to measure the amount of iron in the body.
If you have an iron deficiency (a lack of iron), your iron will be low but your TIBC will be high.
If you have too much iron - for example, if you have a condition such as haemochromatosis, your iron will be high but your TIBC will be low or normal.
As transferrin is produced by the liver, your TIBC level will also be low if you have liver disease.
Read more about the TIBC test at Lab Tests Online UK.