Understand mechanism and manifestations Once a symptom definition is agreed upon, it is important to gain an understanding of the physiological and psychological mechanisms—what is causing (or potentially causing) the symptom. Nurses, in particular, must understand the physiological and pathophysiological process that is potentially creating the symptom experience for the patient because it is the nurse who is usually the primary health-care provider involved in managing the patient’s symptoms. Nurses, by gaining an understanding of the physiological and psychological mechanisms that underlie the expression of the symptom and the manifestations that can be observed, measured and reported objectively can then determine the best symptom management strategies. Understanding the mechanisms and manifestations will also assist nurses in determining what essential information and skills the patient will need to have to do self-care. The extent of information the patient needs relative to mechanism and manifestations depends on the type of the information the patient needs to either understand and/or share their symptom experience and the extent of the essential knowledge and essential skill the patient needs to achieve a positive outcome. These aspects are detailed under their respective topical headings. The nurse must learn and then teach patients to assess the signs associated with their symptom. Signs are objective and observable, in essence, manifestations of their symptom experience. Signs may be physiologically manifested, such as pale skin or dusky-colored lips. Signs may also be pathological indicators of covert diseases, as in the instance of an examination of the patient’s blood indicating that his/her cholesterol level is above normal for a person of his/her age. Patients may not be aware of these signs. It is important to remember that signs cannot be ignored by either the patient or the nurse. Both the patient’s experience of symptoms and the associated signs need to be assessed and tended to.