Mishel's Illness Uncertainty Theory (1988) is a mid-range nursing theory that examines how uncertainty can affect patients. Additionally, Mishel's theory identifies the causes of uncertainty that negatively or positively affect the patient. If a person enters a spiral of known illness, they may perceive uncertainty as an advantage. However, illness-related uncertainty causes depression, fear of illness, emotional distress, loss of control, and inappropriate coping methods (Mishel 1988). If these conditions are left untreated, patients will be unable to form cognitive structures for illness-related events, develop inappropriate psychological adjustments, poor decision-making, and traumatic stress responses (Mishel 1988). Along with his theory, Mishel (1988) developed an uncertainty scale to measure an individual's degree of uncertainty during acute injuries, illnesses, and recurrences of chronic illnesses. There is a desire to know what is happening to one's body, and not understanding the disease will make patients less comfortable. It is the duty of nursing to help patients understand what their illness means to them, expect outcomes, and manage the stress of uncertainty. Mishel's (1981) theory is an important aspect of the nurse's ability to overcome obstacles posed by uncertainty for the benefit of patient well-being. Uncertainty in Chronic Illness Chronic illness puts people in a state of vigilance about their condition. Although chronic illnesses and their consequences are well studied, the psychological effects of uncertainty remain questionable (Baily, Lawrence, Barroso, Bixby, Michel, Muir, Strickland, & Clip, 2009). The intrusion of any chronic illness is a very high stressor that invokes greater perceived severity of symptoms (Johson, Zautra, & Davis, 2006). Nurses entering the field of practice must be prepared to encounter and manage varying levels and symptoms of uncertainty. Managing Uncertainty as Nurses Levels of uncertainty can lead to increased symptoms and many negative psychological effects (Mishel 1988). Nurses entering the field of practice must understand the effects of uncertainty and adapt their efforts to help patients cope with this additional stressor. It is the job of nursing to learn how to create interventions to help patients cope with uncertainty. Using up-to-date research, effectively informing individuals of findings, and teaching self-management techniques is essential to reducing levels of uncertainty among people with chronic illnesses (McNulty, K., Lineh, H., & Wilson, L.. 2004).