What signifies a potential problem if an embolus becomes lodged in an artery?

When an embolus becomes lodged in an artery, it signifies a critical situation where blood flow is obstructed. This blockage can lead to a complete restriction of blood flow downstream of the blockage site. Such a situation can have severe consequences, as it prevents vital tissues from receiving the oxygen and nutrients they need, potentially resulting in tissue damage or death. For example, if an embolus blocks an artery in the heart, it could lead to a heart attack; if it blocks an artery in the brain, it could result in a stroke.

In contrast, other options do not accurately reflect the serious nature of an embolism. Increased blood flow would not occur because the blockage restricts flow. Minor discomfort does not adequately capture the potential severity of the situation, and while a rapid heart rate can be a response to stress or pain, it does not directly signify the problem caused by an embolus. Therefore, the complete blockage is the most accurate representation of the significant issue posed by an embolus lodged in an artery.