Pathology

Pathology (in ancient Greek pathos = feeling, pain, suffering and logos = discourse or treatise [literally: "words"], i.e., system of formal study) is the study of the processes underlying disease and other forms of illness, harmful abnormality, or dysfunction.

Within Biology, it means specifically the study of the structural and functional changes in cells, tissues and organs that underlie Disease. It is a form of Science and a branch of Medicine that involves testing samples in a Medical laboratory and diagnosing health problems from their evidence. Pathologists are trained doctors who have specialized in interpreting test results and physical evidence, and are generally required to take further postgraduate exams and mandatory training before they are able to practice independently.

The related term pathological is sometimes used by clinicians, or casually, to signify some abberrant process underlying such a dysfunction, thus a "pathological growth", or casually, a "pathological attitude" or a "pathological woman hater".

Biological and life studies use

• Etiology: what causes the disease
• Pathogenesis: the mechanism by which a certain etiological factor causes disease
• Morphologic changes: the structural changes induced in the cells, tissues and organs
• Clinical significance: the functional consequences of the morphologic changes

Fields of pathology include:

• Anatomical pathology
• Chemical pathology
• Cytopathology (Cellular pathology?)
• Cytogenetics
• Experimental pathology
• Forensic pathology
• Hematology
• Histology (the study of tissues and the effects of disease upon them)
• Histopathology (the microscopic study of diseased tissue)
• Immunology
• Microbiology
• Nosology (the science of classifying diseases)
• Oral and maxillofacial pathology (a specialty of dentistry and pathology)
• Plant pathology

Related uses

• Speech pathology is a quite separate area mostly involved in helping patients with stroke or speech impediments.
• Psychopathology is also used in Mental health, denoting the study of mental illness.

Pathological is also used to describe a person's actions in such a way as to credit the action to a disease process or a compulsion:

• Pathological purchasing or Pathological consumption
• Pathological narcissism
• Pathological liar

Other uses

• Pathological (mathematics)
• Pathological science

Computer science uses this term in a slightly different sense with regard to the study of algorithms. Here, an Input (or set of inputs) is said to be pathological if it causes atypical behavior from the Algorithm, such as a violation of its average case complexity, or even its correctness. For example, hash tables generally have pathological inputs: sets of keys that collide on hash values. The term is often used pejoratively, as a way of dismissing such inputs as being specially designed to break a routine that is otherwise sound in practice.

See also

• Important publications in pathology