What is Illness - Meaning and definition

Published by Roberto Wenk. Reviewed by Alison Ramsey. Last updated date: January 7, 2019.

Absence of wellness due to disease, another condition, or aging.
An acute illness is one that is recent in onset and likely to be time-limited. If severe, it could be life threatening.
A chronic illness is likely to persist for months to years. With progression it may become life threatening.
An advanced illness is likely to be progressive and life threatening.
A life-threatening illness is likely to lead to death in the near future.

Canadian Hospice Palliative Care Association. A Model to Guide Hospice Palliative Care. Appendices: Lexicon of Commonly Used Terms. Accessed on July 6, 2016.

Published by Roberto Wenk. Last updated date: July 5, 2016.

The term illness refers to the combination of a disease with the experience related to the difference. The latter includes the symptoms caused by the disease as well as psycho-socio-spiritual issues related to the disease.

Beliefs about the illness may affect the way patients and carers behave. Some people think that cancer is infectious and keep the patient in isolation. These misconceptions may result in anxieties, fear and guilt.
A study in cancer patients showed that 23% looked at their illness as a punishment 36% found it a challenge. Those who saw it as a challenge had less pain and depression than those who saw it as a punishment.

Illness trajectories help to understand a patient’s course of illness. Four basic trajectories have been proposed – sudden death, progressive death with accelerated end, progressive decline punctuated with exacerbations and long gradual decline.
In patients with cancer, there is a gradual decline in health over a period of months to years with an accelerated decline over a few weeks and most palliative care services are designed to cater to this pattern of illness.

Glare P, Sinclair C, Downing M, Stone P. Predicting Survival in Patients with Advanced Disease. Hanks G, Cherny NI, Christakis NA, Fallon M, Kaasa S, Portenoy RK (Ed).Oxford Textbook of Palliative Medicine. Fourth Edition, Oxford University Press, 2010, pp. 81-110.

Illness

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