What Is a Pain Scale?

A pain scale is an assessment tool that measures pain levels. Individuals can use a pain scale to self-report detailed accounts of their pain to health care providers. Pain scales help health care providers better understand an individual’s type of pain, level of pain and pain duration. This provides critical information for doctors to provide an accurate diagnosis, form a treatment plan and gauge the effectiveness of treatments.

Pain scales are divided into two main categories: unidimensional and multidimensional. Several types of both unidimensional and multidimensional pain scales are used.

• Unidimensional pain scales
  Unidimensional pain scales are used to rate the intensity of pain. Numeric rating scales, visual analog scales and categorical scales are examples of unidimensional pain scales:
• Numeric rating scale
  This type of pain scale involves the use of numbers to rate pain intensity. The range most often used is from 0 to 10. Zero corresponds to “no pain,” and ten corresponds to “the worst possible pain.”
• Visual analogue scale
  This type of pain scale typically presents as a 10-centimeter straight line. The endpoints on each side of the line define the two extreme limits: no pain and extreme pain. Individuals place an “x” on the line to indicate the level of their pain. The physician then measures where the “x” is on the line to determine a pain score.
• Categorical scale
  A categorical pain scale uses either verbal or visual descriptors for individuals to communicate their level of pain.
• A verbal pain intensity scale uses adjectives, such as “mild,” “moderate,” “severe,” “discomforting,” “distressing” and excruciating,” to describe pain levels. Individuals choose an adjective that best corresponds to the intensity of their pain.
• A visual pain intensity scale shows faces with varying expressions ranging from a face with a big smile to a face filled with tears. These pain scales are especially useful for children.

Multidimensional pain scales

Multidimensional pain scales are not as commonly used as unidimensional pain scales; however, they provide valuable information. Initial pain assessment tools, brief pain inventories and the McGill pain questionnaire are examples of multidimensional pain scales:

• Initial pain assessment tool
  An initial pain assessment tool uses a paper diagram showing the human body. Individuals mark the location of their pain on the diagram and answer a series of questions regarding the characteristics of their pain, the expressions of their pain and the effects of their pain on everyday life.
• Brief pain inventory
  A brief pain inventory is a quick and simple tool for individuals to indicate the intensity of their pain. It uses questions to address facets of pain felt over the past 24 hours.
• McGill pain questionnaire
  The McGill pain questionnaire is a commonly used multidimensional pain scale. It helps evaluate a person's pain based on a set of provided adjectives. Individuals give a numerical rating to each adjective to indicate how the word represents their pain.

Pain is multifaceted and presents differently for each person. Pain scales are an effective tool to help individuals clearly communicate their pain to health care providers.