sleepiness during the day as reported by the patient. This can be further assessed (many times more effectively) by directly inquiring about different circumstances where sleepiness occurs or affects them. Providers can ask patients if they feel sleepiness affects activities such as driving, work, school, or social activities. Many times, the patient may underestimate the severity or even pres­ence of excessive daytime sleepiness. This can be due to the chronic nature of the symptoms, as it may be dif­cult for the patient to know what normal alertness dur­ing the day is supposed to be if symptoms have persisted for years. Sleepiness also affects the ability of the brain to self-assess performance, hence leading to inaccurate judgments by the patient on their ability to stay alert. It can be helpful to ask any family members, friends, or coworkers about the patient’s level of sleepiness, as they may have a different and more accurate perspective. Inquiring about when and how often daytime sleepiness occurs can also be helpful in the evaluation, especially because there are numerous causes for a presenting com­plaint of excessive daytime sleepiness that also need to be considered in the differential diagnosis (See