Travel in the Saada region of northern Yemen is strongly discouraged because of the risk of violent civil unrest. Travel to the eastern parts of the country (Ma'rib, Shabwah, Hadramawt) and the south (Aden, Abyan, Al-Bayda') is also inadvisable because Al-Qaeda is active in some of these areas.
Your doctor will not test for illegal drugs unless you ask him to. A CBC stands for complete blood count which has to do with your blood cells not drugs.
What is a CBC blood test? The complete blood count (CBC) is one of the most common blood test used. It analyzes the three major types of cells in blood: red blood cells, white blood cells, and platelets. The CBC counts these cells, measures hemoglobin (the oxygen-carrying molecule in red blood cells), estimates the red cells' volume,