Theory of Unpleasant Symptoms

Contributor: John R. Blakeman, MSN, RN, PCCN-K
November 29, 2018

Authors – Elizabeth R. Lenz, PhD, RN; Linda C. Pugh, PhD, RNC, FAAN

Year First Published – 1995
Major Concepts

Three categories: a) physiologic factors, b) psychologic factors, and c) situational factors

Four dimensions: a) timing, b) intensity, c) quality, and d) distress



Middle-range Theory: This theory may be used to holistically explore multiple facets of the symptom experience, including the factors influencing symptoms and the consequences of the symptoms. The theory has been used with a wide range of populations and symptoms. As a middle-range theory, it may be used to describe, explain, and predict symptoms in the clinical setting.

Brief Description

The Theory of Unpleasant Symptoms is a holistic middle-range theory that recognizes symptoms as multidimensional. Importantly, the theory was developed with the idea that symptoms share a number of similarities. As such, the theory is sufficiently broad to be used with a wide range of symptoms.

Symptoms include four dimensions: timing, intensity, quality, and distress. Each of these dimensions can be measured. Influencing factors — including physiologic, psychologic, and situational — may affect the symptom experience. Moreover, symptoms themselves may affect performance outcomes, such as care-seeking behaviors or quality of life.

Notably, as the theory has been revised, attention has been paid to the fact that symptoms may interact with one another, perhaps catalyzing each other. Through feedback, symptoms may also affect influencing factors, and changes in performance may also have a reciprocal influence on symptoms and/or influencing factors.

This theory illustrates the complex nature of the symptom experience, which involves innumerable potential variables.

Primary Sources

Lenz, E. R., & Pugh, L. C. (2018). The theory of unpleasant symptoms. In M. J. Smith & P. R. Liehr (Eds.), Middle range theory for nursing (4th ed.). New York, NY: Springer.

Lenz, E. R., Pugh, L. C., Milligan, R. A., Gift, A., & Suppe, F. (1997). The middle-range theory of unpleasant symptoms: An update. Advances in Nursing Science, 19(3), 14-27.

Lenz, E. R., Suppe, F., Gift, A. G., Pugh, L. C., & Milligan, R. A. (1995). Collaborative development of middle-range nursing theories: Toward a theory of unpleasant symptoms. Advances in Nursing Science, 17(3), 1-13.

Pugh, L. C., Milligan, R. A., & Lenz, E. R. (2000). Response to “insomnia, fatigue, anxiety, depression, and quality of life of cancer patients undergoing chemotherapy.” Scholarly Inquiry for Nursing Practice: An International Journal, 14(4), 291-294.

Application Sources

Blakeman, J. R. (2018). An integrative review of the Theory of Unpleasant Symptoms. Journal of Advanced Nursing. Advance online publication. doi:10.1111/jan.13906

Corwin, E. J., Cousino, L., & Rickelman, K. (2002). Predictors of fatigue in healthy young adults: Moderating effects of cigarette smoking and gender. Biological Research for Nursing, 3(4), 222-233. doi:10.1177/109980040200300407

Eckhardt, A. L., DeVon, H. A., Piano, M. R., Ryan, C. J., & Zerwic, J. J. (2014). Fatigue in the presence of coronary heart disease. Nursing Research, 63(2), 83-93. doi:10.1097/NNR.0000000000000019

Ensari, I., Adamson, B. C., & Motl, R. W. (2016). Longitudinal association between depressive symptoms and walking impairment in people with relapsing-remitting multiple sclerosis. Journal of Health Psychology, 21(11), 2732-2741. doi:10.1177/1359105315584837

Gift, A. G., Jablonski, A., Stommel, M., & Given, C. W. (2004). Symptom clusters in elderly patients with lung cancer. Oncology Nursing Forum, 31(2), 203-210.

Hutchinson, S. A., & Wilson, H. S. (1998). The Theory of Unpleasant Symptoms and Alzheimer’s Disease. Scholarly Inquiry for Nursing Practice: An International Journal, 12(2), 143-158.

Lee, S. E., Vincent, C., & Finnegan, L. (2017). An analysis and evaluation of the theory of unpleasant symptoms. Advances in Nursing Science, 40(1), e16-e39. doi:10.1097/ANS.0000000000000141.


Elizabeth R. Lenz

Dr. Elizabeth Lenz is a Professor Emeritus at The Ohio State University, having previously served as a Professor and Dean. She has published widely on nursing theory and measurement. With her colleagues, she developed the Theory of Unpleasant Symptoms, first advancing the theory in the 1990s

Linda C. Pugh

Linda Pugh, School of Nursing. PHOTO BY: JEFF JANOWSKI/UNCW

 Linda C. Pugh, PhD, RNC, FAAN is the Interim Director in the School of Nursing. Prior to this appointment, Dr. Pugh was a tenured professor and the Coordinator of the Doctor of Nursing Practice Program at UNCW’s School of Nursing. She held various positions of leadership at the York College of Pennsylvania (YCP) and at Johns Hopkins University School of Nursing (JHU SON). At YCP, Dr. Pugh was the Director of Graduate Programs and the Doctor of Nursing Practice (DNP) Program. At JHU SON, she was the Director of Professional Programs (graduate and undergraduate). Dr. Pugh has taught all levels of nursing education (prelicensure, RN-BS, Master’s, DNP, and PhD). In Istanbul, Turkey, she joined the Hopkins team in developing a baccalaureate program at Koç University and returned five years later to evaluate the success of that program.

Dr. Pugh has much research experience; having been the Principal Investigator (PI) and Co-PI in several NIH funded studies (the largest involved a community based team of Public Health Nurses and peer counselors). Dr. Pugh has published over 85 publications (articles, books, and book chapters).

Recently, most of her scholarship has revolved around implementing best practices in health care. Dr. Pugh is the co-developer of the Johns Hopkins Nursing Evidence-based Nursing Model and has led or been a team member in numerous practice initiatives that improve the quality of patient care.

Dr. Pugh has been a Fellow in the American Academy of Nursing since 2003. In 2004, she won the prestigious Nightingale Award Program for Excellence in Nursing Practice through Research in the state of Pennsylvania. She was also awarded the Research Utilization Award at Sigma Theta Tau International in 2004.