This study estimates pain prevalence and severity among U.S. adults using data from the 2012 National Health Interview Survey (NHIS). It employs a simple, two-item pain severity coding system developed by the Washington Group on Disability Statistics to categorize pain into five levels: pain-free, low (category 1), moderate (category 2), severe (category 3), and very severe (category 4). The study found that 126.1 million adults (55.7%) reported some pain in the previous 3 months, with 25.3 million (11.2%) experiencing daily (chronic) pain and 23.4 million (10.3%) reporting a lot of pain. Of these, 14.4 million (6.4%) were classified as having the highest level of pain (category 4), while 25.4 million (11.3%) experienced category 3 pain. Adults in categories 3 and 4 were more likely to have worse health status, use more healthcare, and experience more disability than those with less severe pain. The study also examined associations between pain severity and demographic variables, including race, ethnicity, preferred language, sex, and age. It found that females, older individuals, and non-Hispanics were more likely to report any pain, whereas Asians were less likely. The Washington Group pain categories showed good concurrent validity, as they clearly distinguished between different levels of health status, disability, and healthcare use. However, about 50% of individuals in category 4 reported their overall health as good or better, indicating that pain severity does not always correlate with poor health status. The study highlights the importance of considering race, ethnicity, and language preference in pain severity assessments. It found that certain groups, such as non-Hispanic whites who preferred English, were more likely to be pain-free than other groups. Additionally, the study found that individuals with more severe pain were more likely to use healthcare services and experience disability. The Washington Group pain categories were found to be useful for pain research and clinical practice, but further studies are needed to validate their psychometric properties and assess their effectiveness in different populations. The study also notes that the Washington Group approach has limitations, including a lack of multidimensionality, and that additional research is needed to explore its usefulness in pediatric populations and other groups requiring proxy respondents.This study estimates pain prevalence and severity among U.S. adults using data from the 2012 National Health Interview Survey (NHIS). It employs a simple, two-item pain severity coding system developed by the Washington Group on Disability Statistics to categorize pain into five levels: pain-free, low (category 1), moderate (category 2), severe (category 3), and very severe (category 4). The study found that 126.1 million adults (55.7%) reported some pain in the previous 3 months, with 25.3 million (11.2%) experiencing daily (chronic) pain and 23.4 million (10.3%) reporting a lot of pain. Of these, 14.4 million (6.4%) were classified as having the highest level of pain (category 4), while 25.4 million (11.3%) experienced category 3 pain. Adults in categories 3 and 4 were more likely to have worse health status, use more healthcare, and experience more disability than those with less severe pain. The study also examined associations between pain severity and demographic variables, including race, ethnicity, preferred language, sex, and age. It found that females, older individuals, and non-Hispanics were more likely to report any pain, whereas Asians were less likely. The Washington Group pain categories showed good concurrent validity, as they clearly distinguished between different levels of health status, disability, and healthcare use. However, about 50% of individuals in category 4 reported their overall health as good or better, indicating that pain severity does not always correlate with poor health status. The study highlights the importance of considering race, ethnicity, and language preference in pain severity assessments. It found that certain groups, such as non-Hispanic whites who preferred English, were more likely to be pain-free than other groups. Additionally, the study found that individuals with more severe pain were more likely to use healthcare services and experience disability. The Washington Group pain categories were found to be useful for pain research and clinical practice, but further studies are needed to validate their psychometric properties and assess their effectiveness in different populations. The study also notes that the Washington Group approach has limitations, including a lack of multidimensionality, and that additional research is needed to explore its usefulness in pediatric populations and other groups requiring proxy respondents.