For example, wandering at home or sleeping during the day and staying awake all night may be considered eccentric but not intolerable in a person living alone yet problematic in one living with other persons. In a family residence, such behavior may disrupt normal activities. In a nursing home or hospital, staff members may consider such behavior intolerable because it disturbs other patients or interferes with the operation of the institution. Different persons who interact with the patient may have different tolerance levels. For example, one attendant in a nursing home may readily tolerate frequent, repetitive questioning, but another attendant may become frustrated and annoyed by the constant interruptions.
Time of day affects a person's tolerance level.
Environmental factors, particularly those related to safety, also affect tolerability. For demented persons, cooking may be considered an intolerable behavior because it is hazardous to them and to others. Indeed, sundowning is a poorly understood phenomenon associated with dementia, and there is little evidence that sundowning is a discrete phenomenon. At least four functional changes related to dementia may result in behavior disorders. They misunderstand visual and auditory cues.