What can happen if excessive vasodilation occurs?

Excessive vasodilation can lead to a decrease in blood pressure. This occurs because vasodilation causes the blood vessels to widen, which increases the volume within the vascular system and reduces the overall resistance against which the heart must pump. When blood vessels are dilated excessively, the heart may struggle to maintain adequate pressure throughout the circulatory system, resulting in hypotension or low blood pressure. Consequently, this can lead to symptoms such as dizziness, fainting, or even shock if not addressed.

In contrast, the other potential outcomes such as increased blood pressure, increased heart rate, and fluid retention do not occur because these are more associated with compensatory mechanisms the body employs in response to low blood pressure or other factors, rather than being direct effects of excessive vasodilation itself. Thus, when vasodilation is excessive, the primary concern is the resultant drop in blood pressure.