What is a common side effect of Benadryl?

Dizziness is a common side effect of Benadryl, also known as diphenhydramine, which is an antihistamine used primarily to relieve allergy symptoms, including runny nose and sneezing. This medication works by blocking histamine, a substance in the body that causes allergic symptoms, but it also has sedative effects as it crosses the blood-brain barrier. This sedative property can result in dizziness, which is particularly noticeable in older adults.

While some individuals may experience gastrointestinal side effects such as diarrhea or nausea, these are not as commonly reported as dizziness. Amnesia, although it may occur in rare cases due to the drug's sedative effects, is not a typical side effect associated with Benadryl. Therefore, dizziness stands out as a prevalent side effect that users should be aware of, especially when taking the medication and engaging in activities that require alertness.