What is Etiology of Disease?

Denise DeCooman, Artem Cheprasov, Dawn Mills
  • Author
    Denise DeCooman

    Denise DeCooman was a teaching assistant for the General Zoology course at California University of Pennsylvania while she earned her Master's of Science in Clinical Mental Health Counseling from fall semester of 2015 and spring of 2017. She also has a Bachelor's of Science in Biological Sciences from California University. She has been writing instructional content for an educational consultant based out of the greater Pittsburgh area since January 2020.

  • Instructor
    Artem Cheprasov

    Artem has a doctor of veterinary medicine degree.

  • Expert Contributor
    Dawn Mills

    Dawn has taught chemistry and forensic courses at the college level for 9 years. She has a PhD in Chemistry and is an author of peer reviewed publications in chemistry.

Explore etiologies of diseases. Learn the definition of etiology and understand its different categories. Discover various examples of etiologies of diseases. Updated: 02/25/2022

What is Etiology?

When the questions "What is etiology?" or "What does etiology mean?" are posed, the answer is "the cause of something in particular." When specifically asked, "What is the etiology of disease?" the answer one is looking for is "What is the cause of disease?" The definition of etiology, when pertaining to the biological sciences or medicine, is the study of the cause of disease.

The word "etiology" is Greek in origin. This term comes from the root word prefix "etio-" and the suffix "-ology." The prefix "etio-" translates to cause and the suffix "-ology" translates to the scientific study of a particular object or entity.

Background of Etiology

The last time your computer gave you the blue screen of death, did you figure out the cause? Okay, maybe you're not a computer pro. How about this one? The last time you blew a tire on your car, did you figure out whether or not it was a nail, sharp rock, or something else that caused it?

Just like when you search for the cause of a flat tire, doctors and scientists try to similarly figure out the cause of a person's illness. If they know the cause, then they can treat the cause and do more for the patient then just treating their symptoms. Keep this in mind as we discuss the etiology of disease and go over some examples of this concept.

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Exudate: Definition & Types

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:02 Background of Etiology
  • 0:41 Definition of Etiology
  • 3:14 Example of Disease Etiology
  • 5:19 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Timeline
Autoplay
Autoplay
Speed Speed

Epidemiology vs. Etiology

When comparing and contrasting between epidemiology vs etiology, know that epidemiology refers to how diseases are spread and controlled, as well as other factors. Etiology simply desires to find the causes of diseases. Both of these scientific studies are important regarding learning about how diseases can affect human beings.

Categories of a Disease's Etiology

There are three main types of disease etiologies that will be expounded upon in this lesson. These categories of disease etiologies are intrinsic etiology, extrinsic etiology, and idiopathic etiology.

Intrinsic Etiology

Intrinsic etiology means that diseases are caused by an internal source within the person. Examples of intrinsic etiologies of diseases include: genetic disorders, certain types of cancers or neoplastic disorders, endocrine or metabolic disorders, or diseases that affect the immune system.

Heritable factors, which includes genetic problems passed on from previous generations. Diseases of intrinsic etiology can include conditions such as phenylketonuria (PKU), Sickle Cell Anemia, and Tay Sachs Disease. Many of these types of diseases have no current cure.

Certain cancers and neoplastic disorders are also diseases of extrinsic etiology. Both neoplastic disorders and cancer result in abnormal cell growth. Neoplastic disorders can be either benign (and not harmful to the diagnosed individual) or malignant (harmful to the individual).

Endocrine and metabolic problems can also lead to intrinsic etiologies of diseases. The endocrine system produces hormones, which act as chemical messengers, and hormonal issues can lead to certain diseases. For example, Grave's Disease, also known as hypothyroidism, is an endocrine disease which is caused by an underactive thyroid. Diabetes is another medical condition that falls under the umbrella of metabolic and endocrine disorders.

Issues that contribute to problems with the human immune system are also considered diseases of intrinsic etiology. Both seasonal and food allergies are conditions that fall into this particular category regarding diseases of intrinsic etiology. Both conditions contribute to the production of antibodies for substances that are typically harmless to the average and unaffected person.

Sickle Cell Anemia is caused by a genetic abnormality, and thus is considered an intrinsic etiologic agent of disease

Sickle Cell Anemia is caused by a genetic abnormality, and thus is considered an intrinsic etiologic agent of disease

Extrinsic Etiology

Extrinsic etiology refers to causes of disease which are originally found outside of the body of a human. An example of an etiologic agent responsible for a disease of extrinsic etiology would be the rhinovirus, which causes the common cold. Other diseases of extrinsic etiology include: infectious illnesses, animal bites/stings, exposure to radiation/chemicals/electricity, or diseases of iatrogenic nature.

Infectious diseases are conditions that result from extrinsic etiologies. This includes diseases caused by bacteria, fungi, viruses, and other types of pathogens. These illnesses may be spread person-to-person or may result from exposure to infected animals or objects.

Stings or bites from insects or other animals can pose as extrinsic etiologies of certain diseases. While the bite of a mosquito contributes to an itchy bump that usually disappears after a few days, sometimes a more severe problem can occur. The female Anopheles mosquito carries the "Plasmodium" protist which can cause the disease malaria. Regardless of whether one suffers from an itch for a few days, or a transmittable disease that can result in death, these conditions are both of extrinsic etiological nature.

Definition of Etiology

When a doctor tries to figure out the cause of a disease, they are actually trying to figure out the etiology of the disease. Etiology is the cause of a disease or the science that deals with such causes. The word etiology comes from the Greek etio-, which means 'causation' and -ology, which refers to the scientific study of something.

You might be familiar with similar terms such as biology and geology. These words also refer to the scientific study of something. Biology is the study of life (bio) and geology is the study of the earth or rocks (geo).

A disease's etiology, or cause, generally falls into three main categories; intrinsic, extrinsic and idiopathic.

First we will talk about intrinsic etiologies. Intrinsic means coming from within. Therefore, any pathological, or disease-causing, change that has occurred from inside the body has occurred as a result of intrinsic factors.

The following are examples of intrinsic factors:

  • Inherited conditions, or conditions that are passed down to you from your parents. An example of this is hemophilia, a disorder that leads to excessive bleeding.
  • Metabolic and endocrine, or hormone, disorders. These are abnormalities in the chemical signaling and interaction in the body. For example, Diabetes mellitus is an endocrine disease that causes high blood sugar.
  • Neoplastic disorders or cancer where the cells of the body grow out of control.
  • Problems with immunity, such as allergies, which are an overreaction of the immune system..

The second category of disease etiology is extrinsic etiologies. This means the cause of the disease, or pathological change, came from outside of the body.

The following are examples of extrinsic factors:

  • Infectious agents like bacteria, viruses, fungi, and parasites
  • Animal bites or stings
  • Chemicals, electricity, and radiation
  • Iatrogenic causes: This is just a fancy way of saying that the problem resulted from a medical professional's actions or within a medical setting.

The third and final category of disease etiology is idiopathic, or of unknown cause. Remember, we are 'idio'-ts for not knowing the disease etiology. Hopefully, that'll help you remember the definition of this term.

Example of Disease Etiology

You've been given quite a few examples of disease etiology in the last section. Let's go over one more very specific example so you can truly understand how broad a disease's etiological nature may actually be.

To unlock this lesson you must be a Study.com Member.
Create your account

Video Transcript

Background of Etiology

The last time your computer gave you the blue screen of death, did you figure out the cause? Okay, maybe you're not a computer pro. How about this one? The last time you blew a tire on your car, did you figure out whether or not it was a nail, sharp rock, or something else that caused it?

Just like when you search for the cause of a flat tire, doctors and scientists try to similarly figure out the cause of a person's illness. If they know the cause, then they can treat the cause and do more for the patient then just treating their symptoms. Keep this in mind as we discuss the etiology of disease and go over some examples of this concept.

Definition of Etiology

When a doctor tries to figure out the cause of a disease, they are actually trying to figure out the etiology of the disease. Etiology is the cause of a disease or the science that deals with such causes. The word etiology comes from the Greek etio-, which means 'causation' and -ology, which refers to the scientific study of something.

You might be familiar with similar terms such as biology and geology. These words also refer to the scientific study of something. Biology is the study of life (bio) and geology is the study of the earth or rocks (geo).

A disease's etiology, or cause, generally falls into three main categories; intrinsic, extrinsic and idiopathic.

First we will talk about intrinsic etiologies. Intrinsic means coming from within. Therefore, any pathological, or disease-causing, change that has occurred from inside the body has occurred as a result of intrinsic factors.

The following are examples of intrinsic factors:

  • Inherited conditions, or conditions that are passed down to you from your parents. An example of this is hemophilia, a disorder that leads to excessive bleeding.
  • Metabolic and endocrine, or hormone, disorders. These are abnormalities in the chemical signaling and interaction in the body. For example, Diabetes mellitus is an endocrine disease that causes high blood sugar.
  • Neoplastic disorders or cancer where the cells of the body grow out of control.
  • Problems with immunity, such as allergies, which are an overreaction of the immune system..

The second category of disease etiology is extrinsic etiologies. This means the cause of the disease, or pathological change, came from outside of the body.

The following are examples of extrinsic factors:

  • Infectious agents like bacteria, viruses, fungi, and parasites
  • Animal bites or stings
  • Chemicals, electricity, and radiation
  • Iatrogenic causes: This is just a fancy way of saying that the problem resulted from a medical professional's actions or within a medical setting.

The third and final category of disease etiology is idiopathic, or of unknown cause. Remember, we are 'idio'-ts for not knowing the disease etiology. Hopefully, that'll help you remember the definition of this term.

Example of Disease Etiology

You've been given quite a few examples of disease etiology in the last section. Let's go over one more very specific example so you can truly understand how broad a disease's etiological nature may actually be.

To unlock this lesson you must be a Study.com Member.
Create your account

  • Activities
  • FAQs

Etiology of Disease

The etiology of disease examines possible causes for the development of a particular disease. These causes can be intrinsic, extrinsic or Idiopathic. The questions below will help you gain a better understanding using specific examples. Read the scenarios below and do your best to answer the questions. Then, check your responses with those in the Answers section.

Scenarios

1. A patient is exhibiting high blood pressure. What are the causes (etiology) of high blood pressure in an individual?

2. Betty developed cancer due to many chemical exposures over the course of her career based on the doctor's assessment. Is the cause of her cancer based on intrinsic or extrinsic etiology?

3. The doctor could not determine the cause of Rebecca's diagnosis of pulmonary fibrosis. What type of etiology is the doctor using?

4. Chad inherited a specific disease from his maternal line. When he was diagnosed the doctor determine the etiology based on his family history. What type of etiology is this?

Answers

1. Some possible causes of a person having high blood pressure include smoking, high intake of salt and fatty foods (i.e. poor diet), no exercise and high levels of stress.

2. It is extrinsic since chemical exposure was the cause. Radiation came from outside the body.

3. The doctor is using idiopathic etiology. Although he is able to provide a diagnosis, he does not know the exact cause.

4. Instrinsic etiology. Chad inherited the genes responsible for his disease.

What is etiology in biology?

Etiology, in the fields of biology and medicine, refers to the cause of a disease. Etiologies of disease may be intrinsic, or of internal origin, extrinsic, or of external origin, or idiopathic, which means of unknown origin.

What are examples of etiology?

Etiology is the cause of a disease. Examples of etiologies are intrinsic (internal causes), extrinsic (external causes), and idiopathic (unknown cause) etiologies.

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Resources created by teachers for teachers

Over 30,000 video lessons & teaching resources‐all in one place.
Video lessons
Quizzes & Worksheets
Classroom Integration
Lesson Plans

I would definitely recommend Study.com to my colleagues. It’s like a teacher waved a magic wand and did the work for me. I feel like it’s a lifeline.

Jennifer B.
Teacher
Jennifer B.
Create an account to start this course today
Used by over 30 million students worldwide
Create an account