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.
1 Primary polycythemia: In primary polycythemia the increase in red blood cells is due to inherent problems in the process of red blood cell production. 2  Secondary polycythemia: Secondary polycythemia generally occurs as a response to other factors or underlying conditions that promote red blood cell production. Polycythemia can be linked to secondary causes, such as, chronic hypoxia or tumors releasing erythropoietin. 2  Polycythemia vera is due to abnormally increased red cell production in the bone marrow. 3  Treatment of secondary polycythemia is dependent on the underlying condition.