Definition Types and Importance of Pathology

Definition Types and Importance of Pathology

Pathology is the study of disease, particularly structural abnormalities caused by disease. Basically, the word pathology comes from the Greek words pathos, meaning “suffering,” and -logia, “the study of.” In addition to describing the study of disease, the word pathology can also be used to describe the characteristics of the disease itself (e.g., “the pathology of cancer”). The three major subtypes of pathology are anatomical pathology, clinical pathology, and molecular pathology.

Aspects of the disease that can be studied include cell pathology, cell necrosis or cell death, wound healing, cancer formation and inflammation. A combination of anatomical pathology and clinical pathology is called general pathology.

Brief History of Pathology

Pathology has a history dating back to antiquity. The ancient Egyptians were one of the first cultures to record diseases and their effects on the body. Ancient papyrus scrolls contain information about bone damage, disease, and possibly leukemia. Later, in the 5th century BC, the Greek physician Hippocrates was involved in medicine and disease. Many ancient Greek writers, inspired by Hippocrates, wrote detailed articles on diseases such as ulcers, cancer and tuberculosis. Animal surgery also began to be performed. Later, Hippocratic ideas spread to Rome. In the Middle Ages, general education was slow, but Byzantine and Arab physicians also contributed to the study of disease.

The biggest change in pathology was the appearance of the telescope in the 19th century. Now, for the first time, brains can learn details. The focus of understanding disease has shifted from studying the whole body to focusing on the human brain. With the development and proliferation of microscopes, the study of pathology has increased exponentially, leading to large-scale investigations such as changes in organs and tissues.

Types of Pathology

Some important types and sub-branches of pathology include:

Anatomical Pathology

Anatomical pathology is the study of anatomical features, such as B. Tissue removed from the body, or even a whole body in the case of an autopsy, to diagnose the disease and increase knowledge about this disease. Anatomical pathology can involve viewing cells under a microscope, but also viewing organs in general (e.g., a ruptured spleen).

Anatomical Pathology

This also includes studying the chemical properties of cells and their immunological markers. There are several broad subcategories of anatomical pathology:

Surgical pathology is the study of tissues removed during surgery. A common example is examining a small piece of tumor tissue to determine whether the tumor is malignant (cancerous) or benign and to make a diagnosis. This procedure is called a biopsy.

Cytopathology is the study of small groups of cells that are shed in body fluids or obtained by scraping, such as those collected on a cervical pap smear. A pap smear detects cervical cancer and some types of infections. The cells are taken by swabbing the cervix and then processed and examined under a microscope for abnormalities.

Histopathology is the examination under a microscope of cells that have been stained with dye to make them visible or easier to see. Antibodies are often used to label different parts of the cells with different dyes or fluorescence. After the microscope became widely used in pathology, many different methods of preserving and staining tissue were developed.

Clinical Pathology

Clinical pathology diagnoses disease through laboratory analysis of body fluids and tissues. For example, the chemical components of blood can be analyzed, along with the analysis of cells and the identification of microorganisms, such as bacteria, present in a sample. The field of clinical pathology is sometimes also referred to as the field of laboratory medicine. The main types include the following:

Chemical pathology, or clinical chemistry, involves the chemical analysis of body fluids through testing and microscopy. Typically, chemical pathology involves the study of blood and its immune components, such as white blood cells.

You may also read more Pathology related articles here


Immunology or immunopathology is the study of diseases of the immune system. It deals with immune responses to foreign molecules, allergies, immunodeficiency, and organ transplant rejection.

Hematology is also related to the study of the blood but has more to do with the specific identification of blood diseases than chemical pathology. Hematologists also study the lymphatic system and bone marrow, which are other parts of the hematopoietic system.

Molecular Pathology

Molecular pathology is the study of abnormalities in tissues and cells at the molecular level. It is a broad category used to refer to the study of disease of any organ or tissue in the body by examining what molecules are present in cells and It can combine aspects of both anatomical & clinical pathology. Some techniques that can be used in molecular pathology include polymerase chain reaction (PCR) to amplify DNA, fluorescent labeling, karyotype imaging of chromosomes, and DNA microarrays (small samples of DNA placed on biochips).

Importance of Pathology

Pathology is a very broad field and over 19 types of specializations apparently coexist, pathologists do not have the same work. Depending on their specialization, skills, and interests, they work in laboratories, hospitals, clinics, or pathology centers. They often give the doctor valuable advice and also decide on the best possible treatment for complicated diseases.
Of the different specializations, the most important are chemical pathology, hematology (diseases related to blood and its components), histopathology, medical microbiology (study of infections), toxicology, molecular genetics, immunogenetics and histocompatibility. Apart from these, there are a few more that have their own importance.

In addition to screening and identifying possible infections or serious diseases, pathology also comes into play with blood transfusions, blood and organ storage. It is also important in the development of vaccines for various infections and diseases. Thus, any hospital with its own pathology laboratory is always an advantage over others that lack this capability.


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