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. But some of the smaller studies conducted over the past two decades show that no sperm is "progressing" and that some doctors have begun to say that it will not lead to pregnancy. Lack of sleep builds stress and lowers testosterone in your body.