• Health Science
• Medicine & the Allied Health Sciences

There are both professional and legal obligations to the client. Because health science professionals are entrusted with the personal secrets of their patients, and because their decisions directly influence their clients' lives, almost all countries have some kind of licensing requirement for practitioners of the allied health sciences. Through these licensing requirements, the scope of practice for each of the health science professions is regulated.

In the United States, licensing is under the jurisdiction of each state.

Even if these practices are quite effective , they are not part of health science. A chiropracter can often rid a patient of troublesome back pain but, because the chiropracter's view of the causes of pain and the workings of the human body does not have a firm grounding in human biology, Chiropractic is not included here as one of the allied health sciences, but instead as part of alternative medicine. Similarly, yoga positions and meditations sometimes have a therapeutic effect on the body, but the concepts of chi and the way that the body is visualized are not based on biology.

Collaboration between the allied health science professions can act as a check and balance against medical errors and offer better health care. For example, when a patient in the hospital is given a powerful drug through an intravenous drip, several different kinds of health professionals are directly involved in that single treatment. Most typically the physician orders the drug, the pharmacist prepares it, and the nurse administers it. Each of these professionals evaluates the patient either directly by an interview and examination, or indirectly through review of the medical record. Each professional brings a different perspective to the same treatment, and, working together, increases the liklihood that the patient will receive proper care. When treatment of a disease is very complex, and requires many different treatments along with a variety of different tests and examinations of the body, effective care demands the co-ordinated efforts of an entire team of health science professionals.