When the TSH test reveals abnormal results, a doctor may order the T4 test. It measures the quantity of thyroxine inside blood. There are two types of T4 tests. One that measures the free thyroxine and something that measures the complete thyroxine available. The total thyroxine test is impacted by proteins which can be guaranteed to thyroxine. The free thyroxine test is known as more accurate since it isn't afflicted with protein levels. Osteoarthritis initially affects the smooth cartilage lining of joints. This makes exercise more difficult than usual, causing pain and stiffness.