Final answer:
The nurse should report Benign Prostatic Hyperplasia in the client's medical record before initiating dimenhydrinate for motion sickness, as it may exacerbate urinary retention issues associated with BPH.
Step-by-step explanation:
In the context of a nurse reviewing a medical record for a client prescribed dimenhydrinate for motion sickness, the condition that should be reported to the provider is Benign Prostatic Hyperplasia (BPH). Dimenhydrinate, an antihistamine, can exacerbate symptoms of BPH, such as difficulty urinating, because it has anticholinergic effects which may increase urinary retention. This could cause complications for the client. Conditions like Major Depressive Disorder, Diabetes Mellitus, and Meniere's disease do not directly contraindicate the use of dimenhydrinate, but the healthcare provider should be aware of all existing conditions to manage potential interrelated side effects carefully.