It would be wrong for me to speculate about the reasons why your doctor has requested these tests. I might not be of particular help to you by engaging in second-guessing of the reasoning behind the decision. I will make the general comment that sometimes thyroid disorders can sometimes affect mood, which may explain the reason for the test. The second part to your question is more straightforward. The thyroid and blood sugar checks simply involve taking a blood sample, which is usually extracted from an arm vein using a needle and syringe. Sometimes the blood sugar may be requested as a random sample and sometimes it may be requested as a fasting sample. A random blood sugar means that no fasting is required whereas the fasting sample is taken following a specified period of fasting, which could be overnight or as little as two hours. The results of the tests are usually posted to your doctor directly and you should be able to obtain the test results within a week.