Immediate medical services for the examination, diagnosis, care, and treatment of a patient because of severe episodes of illness. Usually, acute care is given in a hospital by specialized personnel and use of sophisticated technical equipment. It may be intensive care, critical care, or emergency care.

Sickness that is usually of short-term duration and that often comes on quickly.

Organization formed to protect patient access to quality long-term hospital care; formerly known as Long Term Acute Care Hospital Association of America (LTACHA). Long Term Acute Care Hospitals (LTACHs) are hospitals that provide patients with acute care for extended inpatient stays (defined by federal statute as an average of 25 days or more). ALTHA works to protect the rights of medically complex patients and the hospitals that treat them by educating federal and state regulators, members of Congress, and health care industry colleagues. ALTHA also works to increase quality of care by sharing and improving best practices among its hospital members.