A major complication in studies to identify the nature of bladder sensations is language. It is difficult, if not near impossible, for the lay person, with no knowledge of physiology, anatomy or pathology, to put into simple terms a description of basic visceral sensations. Therefore, before the investigators can speculate about the detailed mechanisms generating sensation the investigators must overcome this language and communication difficulty. This will be addressed in the present study.

There are important reasons why the investigators must identify the mechanisms generating the different sensations as the bladder fills. One of them is that these are basic physiological mechanisms which need to be better understood.

Inclusion Criteria:

Healthy volunteers

• Healthy students from The University of Maastricht well versed in Dutch.

Patients

• Patients with OAB diagnosed by their urologist using the criteria of more than 8 micturitions on three consecutive days. Before the start of any anticholinergic or other therapy. Patients on anticholinergic therapy will be asked to stop this therapy for at least 10 days before they enter the first session.
• Well versed in Dutch.

Exclusion Criteria:

Healthy volunteers

• Use of any medication (except oral contraceptives)
• Surgical history of the abdomen
• Urinary complaints (e.g. frequency, urgency)
• Urinary tract infection

Patients:

• Congestive heart disease or history of heart failure
• Presence of urinary tract infection. These patients will be treated by antibiotics.

Healthy volunteers

Patients with overactive bladder