Detection Windows The window to detect the presence of a particular drug in a personâs urine is highly dependent on multiple factors, such as: Hydration-More dilute urine from high fluid intake may cause dilution of drug and therefore a negative result due to levels present but below the cutoff.
Alcohol flush reaction. Alcohol flush reaction is a condition in which an individual develops flushes or blotches associated with erythema on the face, neck, shoulders, and in some cases, the entire body after consuming alcoholic beverages.
Facial flushing: Facial flushing can be due to intense emtions, such as anger or embrassment. Too much alcohol, caffeine, medicaions, including niacin, can cause it too. Medical conditions such as emphysema, carcinoid syndrome and mastocytosis can do that to you.