Estimated tax is the method used to pay Social Security and Medicare taxes and income tax, because you do not have an employer withholding these taxes for you. Form 1040-ES, Estimated Tax for Individuals (PDF), is used to figure these taxes. Form 1040-ES contains a worksheet that is similar to Form 1040.
Why It's Done. The main reason doctors order the IGFBP-3 test is for its usefulness as an indicator of whether someone is producing a normal amount of human growth hormone. In this way, the IGFBP-3 test is used to check for pituitary gland disorders and abnormalities in growth hormone production.
A bilirubin test is used to detect an increased level in the blood. It may be used to help determine the cause of jaundice and/or help diagnose conditions such as liver disease, hemolytic anemia, and blockage of the bile ducts. Bilirubin is an orange-yellow pigment, a waste product primarily produced by the normal breakdown of heme.