Pathology
Pathology is the medical science of disease, studying causes, tissue changes, laboratory findings, diagnosis, progression, and the evidence that connects symptoms to underlying processes.
What pathology is
Pathology is the study of disease. It asks what has changed in the body, why it changed, how the change can be detected, and what it means for diagnosis, treatment, and prognosis. The field connects visible symptoms with microscopic tissue changes, laboratory measurements, molecular findings, infection, injury, genetics, immune reactions, and environmental exposures.
Disease mechanisms
Pathology looks for mechanisms rather than only names. Inflammation, cell death, abnormal growth, infection, clotting, scarring, degeneration, immune attack, toxin exposure, and genetic change are examples of processes that can damage tissues. Understanding the mechanism can explain why a disease behaves the way it does and which treatments might help.
Tissues, cells, and slides
A common image of pathology is a microscope slide. Tissue from a biopsy, surgery, or autopsy may be processed, sliced thinly, stained, and examined for architecture, cell shape, margins, invasion, infection, inflammation, or cancer features. Histology and cytology turn tiny samples into evidence that can guide major decisions.
Laboratory medicine
Many pathologists work with clinical laboratories. Blood counts, chemistry panels, microbiology cultures, coagulation tests, transfusion testing, genetic tests, and molecular assays all need careful collection, measurement, interpretation, and quality control. A lab result is strongest when it is connected to the patientเน€เธยเนยเธเธขยs history, examination, imaging, and timing.
Anatomic and clinical pathology
Pathology is often divided into anatomic pathology and clinical pathology. Anatomic pathology focuses on organs, tissues, cells, biopsies, surgical specimens, cytology, and autopsies. Clinical pathology focuses on laboratory testing of blood, urine, body fluids, microbes, chemicals, immune markers, and genes. Many diagnoses depend on both perspectives.
Cancer, infection, and inflammation
Pathology is central to cancer diagnosis because tissue features can show tumor type, grade, stage, margins, and molecular markers. It also helps identify infectious agents, patterns of immune response, organ damage, and inflammatory disease. The same symptom, such as swelling or pain, can have very different pathological explanations.
Autopsy and investigation
Autopsy pathology studies the body after death to understand disease, injury, treatment effects, unexpected complications, or cause of death. Autopsies can support families, clinicians, public health, quality improvement, and legal investigations. They can also reveal diseases that were missed or unclear during life.
Why it matters
Pathology matters because health care needs evidence about what is actually happening inside the body. A precise diagnosis can prevent unnecessary treatment, direct urgent care, identify inherited or infectious risks, explain a death, and turn a vague illness into a clearer plan.