Indicator

Indicator is a term used in various fields, including chemistry, medicine, and economics, to denote a measure or sign that reveals the state or level of something. In medicine, an indicator can refer to a substance, characteristic, or process that provides evidence of a disease or physiological state.

Chemical Indicators

In Chemistry, an indicator is a substance that changes color in response to a chemical change. An acid-base indicator (e.g., litmus paper) changes color depending on the pH of the solution. Redox indicators are also frequently used, a common example is the substance diphenylamine, which turns blue in response to oxidation.

Medical Indicators

In Medicine, an indicator is a measure, symptom or sign that can be observed in a patient and is associated with a particular disease or medical condition. Indicators in medicine can be as simple as a fever indicating an infection, or as complex as a detailed analysis of blood work.

Economic Indicators

In Economics, an indicator is a statistic about economic activity. Economic indicators allow analysis of economic performance and predictions of future performance. Examples include unemployment rates, GDP and inflation rates.

Environmental Indicators

In Environmental Science, an indicator is an organism or species whose presence, absence or abundance reflects a specific environmental condition. Indicator species can signal a change in environmental conditions such as pollution or climate change.

See Also

• Bioindicator
• Health Indicator
• Economic Indicator
• Chemical Indicator