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.
For many people, polycythemia vera may not cause any signs or symptoms. However, some people may experience: 1  Itchiness, especially following a warm bath or shower. 2  Headache. 3  Dizziness. 4  Weakness. 5  Excessive sweating. 6  Painful swelling of one joint, often the big toe.7  Shortness of breath.ake an appointment with your doctor for an evaluation if you have any of the signs or symptoms of polycythemia vera. Because polycythemia vera causes your blood to thicken and slows blood flow, it increases your risk of developing blood clots. If a blood clot occurs in your head, it can cause a stroke.