The public healthcare system allows patients to be treated without an appointment in public general hospitals by general practitioners and specialists in the outpatient clinic (''Consulta Externa'') at no cost. This is done in the four basic specialties of pediatric, gynecology, clinic medicine, and surgery. There are also public hospitals specialized to treat chronic diseases, target a particular group of the population, or provide better treatment in some medical specialties. Some examples in this group are the Gynecologic Hospitals, or Maternities, Children Hospitals, Geriatric Hospitals, and Oncology Institutes.