what can I do with a bachelor’s degree in health science?

It depends on what you decide to specialize in- you could continue your education to become a physician, PA, or nurse, be a nutritionist, run a hospital, etc. Here is some info about the different options:

http://www.tourou.edu/chs/bshs.htm

The Bachelor of Science in Health Science and Administration, designed primarily for students pursuing clinical, administrative, and research careers in health care, provides a broad-based examination of human functioning and behavior with an emphasis on fundamental principles and applications from biology, psychology, and chemistry. The program also offers students an opportunity to explore social, political, economic, and ethical questions associated with health care, and to address implications for individual practice and public policy. Finally, the program equips students with an academic foundation for graduate or professional school, or for work in a variety of health care professions including but not limited to medicine, dentistry, physical therapy, occupational therapy, health care management, community health, public health, and biomedical research.