A qualitative drug screen is used to detect the presence of a drug in the body. A blood or urine sample may be used. However, urine is the best specimen for broad qualitative screening, as blood is relatively insensitive for many common drugs, including psychotropic agents, opioids, and stimulants. Common methods of drug analysis include chromatography, immunoassay, chemical (spot) tests, and spectrometry.
Polycythemia Vera Complications. If you have PV, the thickness of your blood and the slowed blood flow can cause serious health problems. Blood clots are the most serious complication of PV. Blood clots can cause a heart attack or stroke. They also can cause your liver and spleen to enlarge.
Most people with polycythemia vera have too many red blood cells, but the disease may also cause you to have too many white blood cells and platelets. In rare cases, parents pass this broken gene to children.