Consider a doctor’s office without a phone. Patients, future patients, outside organizations, and other essential parties would have no way of asking inquiries, learning about services, or scheduling an appointment unless they came into the office. There would be no way for people to communicate with the office. In this day and age, not having a website is the equivalent of not having a phone at your office.
A professional, medical website provides patients, both current and potential, with information about your practice, information about their medical needs, and most importantly, a way for patients to contact you in order to request consultations.