What is the Difference Between Pathophysiology and Pathogenesis

The main difference between pathophysiology and pathogenesis is that pathophysiology describes the physiological process associated with a particular disease or injury whereas pathogenesis describes the development of the disease. Furthermore, etiology is the medical discipline that describes the causes or the origination of the disease.

Pathophysiology and pathogenesis are medical disciplines that describe the characteristics of diseases. Due to their close relationship, it is hard to identify the difference between pathophysiology and pathogenesis without using specific examples.

Key Areas Covered

1. What is Pathophysiology
     – Definition, Features, Examples
2. What is Pathogenesis
     – Definition, Features, Examples
3. What are the Similarities Between Pathophysiology and Pathogenesis
     – Outline of Common Features
4. What is the Difference Between Pathophysiology and Pathogenesis
     – Comparison of Key Differences

Key Terms

Disease Development, Etiology, Origin of Diseases, Pathogenesis, Pathophysiology, Physiology

What is Pathophysiology

Pathophysiology is the physiological process exerted in the body in response to a particular disease. It is a convergence of pathology and physiology. Beyond words, pathology is the collection of medical conditions of the body during the disease state and physiology describes the mechanisms operating in the host body. Therefore, pathophysiology describes the abnormal functional changes occurring within the host during the disease state. These functional changes are responsible for the emergence of symptoms.

Figure 1: A Malaria Sporozoite Migrating through the Midgut Epithelium

Moreover, pathophysiology describes different types of disease states including acute, chronic, and recurrent. When considering an infection, one can describe its pathophysiology under two stages. They are colonization and disease state. After the invasion of the host, colonization refers to the successful growth and multiplication of the pathogenic microorganism. At this stage, the immune system of the host develops various immune responses against colonization. And, this exerts various pathophysiological conditions like inflammation. Some of the symptoms of inflammation are redness, heat, swelling, pain, and loss of function. Secondly, the pathophysiological conditions related to the disease state depend on the type of pathogenic microorganism. For example, some symptoms of the tetanus disease are jaw cramping, muscle spasms, muscle stiffness, seizures, fever, sweating, etc.

What is Pathogenesis

Pathogenesis is the biological mechanism that leads to the development of the disease. Etiology and progression are the two main aspects of pathogenesis. Moreover, etiology describes the causes or the origination of the disease. In addition, the properties of the tissue or the cellular environment become an important factor in the progression of the disease.

Figure 2: Pathogenesis and Pathophysiology of Infection

Several mechanisms of pathogenesis are inflammation, infections, malignancy, and tissue breakdown. Therefore, in simple terms, pathogenesis is the mechanism used by microorganisms to cause an infection. During an infection, pathogenic microorganisms invade the body tissues and proliferate inside it. Hence, this is the origin of the infection or the etiology. Secondly, these pathogenic microorganisms use various mechanisms to evade the immune response generated by the host. Therefore, this helps them to survive and replicate inside the host, invading the healthy tissues further. Like this, pathogenic microorganisms progress inside the host.

Similarities Between Pathophysiology and Pathogenesis

• Pathophysiology and pathogenesis are two medical disciplines that describe the characteristics of diseases.
• When describing a disease, etiology or the origin of the disease has to come first. Secondly, pathogenesis describes the development of the disease. Finally, pathophysiology describes the physiological process of the disease.
• Also, both pathophysiology and pathogenesis are important in the prevention, management, and treatment of a particular disease.

Difference Between Pathophysiology and Pathogenesis

Definition

Pathophysiology refers to the disordered physiological processes associated with disease or injury while pathogenesis refers to the manner of development of a disease. These definitions explain the main difference between pathophysiology and pathogenesis.

Significance

Moreover, another difference between pathophysiology and pathogenesis is that pathophysiology describes the functional process exerted by the disease in the body while pathogenesis describes the chains of events leading to the disease.

Consequence

While describing a disease, pathophysiology comes after pathogenesis while pathogenesis comes after etiology. Thus, this is also a difference between pathophysiology and pathogenesis.

Conclusion

Pathophysiology is the physiological process exerted in the body in response to a particular disease. On the other hand, pathogenesis describes the development of the disease. Furthermore, etiology describes the origin or the causes of the disease. Therefore, the main difference between pathophysiology and pathogenesis is the types of events described by each medical discipline.

Reference:

1. Bloch, Karen C. “Infectious Diseases”, Pathophysiology of Disease: an Introduction to Clinical Medicine. Chapter 4, McGraw-Hill Education Medical, 2019. Available Here

Image Courtesy:

1. “Malaria” By image by Ute Frevert;false color by Margaret Shear –  (CC BY 2.5) via Commons Wikimedia  
2. “Pathogenic Infection” By Uhelskie – Own work (CC BY-SA 4.0) via Commons Wikimedia