Which Science Courses Do Nursing Programs Require, and Why?
The short answer
The science core of nursing prerequisites is anatomy and physiology (two semesters with labs), microbiology with a lab, and some form of chemistry, with statistics usually counted alongside them. These courses are weighted heavily in admissions because the nursing curriculum treats their content as already known and moves directly into clinical application.
Anatomy and physiology
Normally a two-course sequence. The first covers cells, tissues, the integumentary, skeletal, muscular, and nervous systems; the second covers cardiovascular, respiratory, digestive, urinary, endocrine, and reproductive systems along with fluid and electrolyte balance.
This is the course that reappears constantly. The nursing process described by the American Nurses Association begins with assessment, and assessment means interpreting what a body is doing against a baseline of normal structure and function. Programs weight A&P grades accordingly, and some calculate a separate science GPA from these courses alone.
Summary: the highest-workload prerequisite and usually the most heavily weighted.
Microbiology
One semester, normally with a lab. Covers bacteria, viruses, fungi and parasites; growth conditions; transmission routes; aseptic technique; and the mechanisms by which antimicrobials work and resistance develops.
Its practical descendant is infection control, which appears throughout nursing coursework and in the safety and infection control content of the NCSBN's published NCLEX test plans.
Summary: the foundation for everything a program later teaches about preventing transmission.
Chemistry
Requirements vary more here than anywhere else on the list. Some programs require a full general chemistry course with a lab; others accept a one-semester chemistry-for-health-sciences or introductory organic and biochemistry course; a few waive it entirely for ADN applicants.
Chemistry underpins two later areas. One is physiology at the molecular level — acid-base balance, electrolytes, gas exchange. The other is pharmacology, where drug classes, interactions, and formulations only make sense with some chemical vocabulary. The manufacturer labeling that defines how an approved drug is characterized in the United States is published in full on DailyMed, the National Library of Medicine's repository of FDA-submitted package inserts — a document format that nursing students learn to read and that assumes exactly this background.
Summary: check each program individually, because the chemistry requirement is the least standardized.
Statistics and quantitative work
Statistics is required by most BSN programs and many ADN programs. It supports evidence-based practice coursework and the ability to read research literature. Separately, many programs require or strongly recommend a dosage calculation or math competency check, usually administered as an internal test rather than a transferable course.
The reason programs take arithmetic competence seriously is structural: medication administration is the point in nursing work where small errors matter most. The nonprofit medication-safety organization ISMP maintains the List of High-Alert Medications in Acute Care Settings, which identifies drug classes that carry a heightened risk of significant harm when used in error and that institutions therefore surround with extra safeguards. Nursing programs teach those safeguards; prerequisite math is what makes the teaching land.
Summary: statistics for reading evidence, arithmetic for everything else.
Where the science shows up again
Prerequisite science is not a gate you pass and forget. Three examples of where it resurfaces:
- Lab values. Students learn to recognize what common panels measure and what moves them. The NIH's MedlinePlus medical tests library is a plain-language reference for the same tests, written for the public.
- Drug labeling. Reading an indication, contraindication, and warning section fluently is a taught skill built on chemistry and physiology.
- Infection control protocols, which are microbiology applied to a specific setting.
A note on what this page is and is not: it explains why these prerequisite courses exist. It is not clinical guidance, and nothing here should be used to interpret a test result or a medication. Those are judgments for licensed practitioners.
If your science credits are old
Many programs apply a recency limit to science prerequisites, commonly a window of several years, and will require the course to be retaken if it falls outside. That policy is covered in how credits, GPA, and recency rules work.