Leaves show yellowing on the edges accompanied by upward curling.
The yellowing and subsequent casting of leaves, for instance, is a very general symptom of disease in plants, and may be induced by drought, extremes of temperature, insufficient or excessive illumination, excess of water at the roots, the action of parasitic Fungi, insects, worms, &c., or of poisonous gases, and so forth; and extreme caution is necessary in.
When present, the symptoms are non-specific and usually include fever, tiredness, loss of appetite, nausea, abdominal discomfort, dark urine, clay-colored bowel movements, and jaundice (yellowing of the skin and eyes).
Signs include a darkening of the urine and jaundice (yellowing of the skin and whites of the eyes).
Yellowing is gradual and dependent on your lifestyle, but certainly Crest Whites Strips whitening effects lasted for a year on my teeth.