Primary care is defined as the care given by the first physician whom the patient ordinarily consults. The primary care physician is expected to possess some knowledge of a broad range of medical problems. Primary care physicians provide excellent care for many medical conditions, especially common problems. It is more difficult, however, for a primary care physician to keep abreast of modern methods of diagnosis and treatment of diseases with a low incidence. For example, in the United States, the average primary care physician sees one new case of epilepsy every 2 years. In the United Kingdom, a general medical practitioner (GP) might expect to diagnose one or two new cases each year, as well as having a caseload of 8 to 12 people with active epilepsy. The responsibility for long-term prescribing for patients varies from country to country. In the United Kingdom, this is an important responsibility of primary care physicians, but in other settings it is usually devolved to secondary care providers.

The ratio of primary care physicians to specialty physicians varies widely from country to country and within countries, especially between urban and rural areas. This ratio affects national policy regarding the management of chronic disease of relatively low incidence. In some countries, primary care is provided by nurses, health visitors, and also by other health care workers. In some resource-poor countries, practitioners of traditional medicine may also play a role.

Secondary care denotes the most common type of specialty care. A general surgeon, general internist (physician), pediatrician, and, in some parts of the world, a neurologist would be considered to provide secondary care. In some countries, the dividing line is not sharp; in the United States, a general internist may practice some primary care medicine. Nonetheless, the underlying concept is that the practice is limited to certain problems so as to allow for greater in-depth knowledge on the part of the physician. Even so, in secondary care, the range of problems dealt with is relatively broad.

Tertiary care is the most specialized level. In epilepsy care, physicians with a prior qualification in neurology usually provide this, although physicians from other specialties are often involved (notably neurosurgery, psychiatry, clinical neurophysiology, and internal medicine). In most countries, tertiary care is available in teaching or university settings.