What Is Sonography?

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pregnant couple undergoing sonography

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Sonography is a type of medical imaging test that uses high-frequency sound waves to create pictures of different internal parts of the body, like the uterus, heart, intestines, and other organs. Sonography uses ultrasound technology to create an image known as a sonogram. This technology is one of the most common imaging tests used to diagnose and treat medical conditions. 

A radiologist may perform sonography, but there are also sonographers and ultrasound technicians who specialize in this form of medical imaging and receive more robust training to administer the test. Sonography is considered to be generally safe for most people. Additionally, the test doesn’t require much preparation and needs virtually no recovery time. 

Key Terms

Sonography and ultrasound are often used interchangeably. However, there is a slight difference between these key terms. Here's what you need to know:

  • Sonography: The scientific process of developing medical images
  • Ultrasound: The technology that sonographers (people who specialize in sonography) use to generate medical images
  • Sonogram: The medical image that is produced after the completion of the ultrasound


Healthcare providers use sonography to assess the health of your internal organs. If you’ve been injured, have an infection, or are experiencing symptoms suggestive of illness, your provider may schedule you for an ultrasound to get a better look at the area of concern.

During the test, it's common to check for inflammation, organ damage, changes in blood flow, and abnormal growths. If you’re expecting a baby, an ultrasound will examine the development of your baby and measure your amniotic fluid throughout your pregnancy.Since ultrasounds are safe and non-invasive (meaning, a provider doesn't cut into your skin to perform the test), people of all ages can get them.

Types of Sonography

Sonography is usually divided into two broad categories: ultrasounds for pregnancy and ultrasounds for diagnosing other types of medical conditions.

Pregnancy Ultrasound 

A pregnancy ultrasound allows your provider to see how your baby is growing, estimate your gestational age, and identify birth defects, among other concerns. Most pregnant people have ultrasounds between 10 and 13 weeks of gestation and 18 and 22 weeks of gestation. You may have additional ultrasounds, too—especially if you’re not sure when you became pregnant or have a high-risk pregnancy. 

Diagnostic Ultrasound

A healthcare provider can order a diagnostic ultrasound to identify a variety of medical conditions, including:

How Does It Work?

Sonography is a fairly simple procedure that doesn’t require much from the person being tested. You will have to keep the part of your body being imaged relatively still, but ultrasounds are not as restrictive as other tests, like MRIs. 

Before the Test

You should arrive at your ultrasound prepared to lie on a table. Depending on the part of your body that is being tested, your provider may ask you to lie on your back, stomach, or side. 

Your sonographer should let you know in advance of any fasting requirements for your ultrasound. You may have no requirements, or you may need to avoid eating or drinking for a certain amount of time before the test. Sometimes you will need to have a full bladder for all or part of the test. 

Most people don’t need to be sedated for an ultrasound unless they’re unable to remain still for the test. This typically only applies to very young children who may not be able to stay still for the duration of the exam. Ultrasounds generally last between 30 and 60 minutes.  

During the Test 

When the sonographer is ready to begin, they will apply a gel-based lubricant to your skin in the area being tested. Then they will use a wand called a transducer, which emits high-frequency sound waves that help take the images. 

During external sonography (e.g., on your stomach), you can expect your sonographer to move the transducer over your skin outside the area being tested and apply small amounts of pressure in different positions to obtain the necessary images. For internal sonography (e.g., in your vagina or rectum), your sonographer will insert the transducer inside of you to capture the images. 

The images will appear on a small screen in front of the sonographer. You may or may not be able to see them as you’re being tested. The sonographer will be seated right next to you, so you can ask them questions or communicate any concerns during the test. Ultrasounds aren’t painful, but can sometimes cause a little discomfort or pressure. If you’re uncomfortable, you can let the sonographer know and they may be able to modify the test or give you a short break. 

After the Test

Once the ultrasound is complete, the sonographer will help you clean off the gel lubricant and move into a more comfortable seated position. If you need to change back into your clothes, they will leave the room so you can do so in private. 

You can resume all your normal activities right after the ultrasound. You won't have to wait in the office or stay overnight and you can drive yourself home after the procedure. The sonographer may share the results of your ultrasound with you on the spot, or you may have to wait for your primary care provider to follow-up with you by phone or appointment.

Risks and Precautions

For the most part, ultrasounds are extremely safe and don’t pose a health risk. They don’t use ionizing radiation like X-rays do, so there’s no need for you to worry about the effects of the ultrasound on your body. There is a slight chance you could be allergic to the gel used during the ultrasound procedure, which could result in contact dermatitis (skin rash) after the test and require minor treatment.

However, ultrasounds generate a small amount of heat that can affect your skin and tissues in the area where the test is being conducted. That said, experts recommend undergoing ultrasounds only when medically necessary. While anyone of any age can safely have an ultrasound—and they are considered safe even for pregnant women and unborn children—you shouldn’t have more ultrasounds than necessary during pregnancy and shouldn’t utilize an at-home imaging device to monitor your pregnancy on your own. 

How to Prepare for Sonography

The good news: there isn’t much preparation needed for sonography. Depending on the test, your provider may recommend fasting for a certain amount of time before your test or refraining from emptying your bladder before you go. But many ultrasounds don’t require this.

Ultrasounds can be performed at a variety of locations, so it's best to know where your test will be performed well before your appointment. This can sometimes be at a hospital, clinic, or private doctor's office. In some cases, radiology satellite clinics can perform an ultrasound in your home.

Keep in mind: you may or may not need to change into a hospital gown, so plan to wear comfortable clothes that are easy to take off. You may also need to remove any jewelry and accessories that could interfere with the sonographer’s ability to image that area.

Bring your insurance card with you to the exam if you have insurance coverage and are planning to utilize it. If you have a copay, you should expect to pay for the procedure prior to the test, so it's best to have a form of payment ready to go. If you’re paying out-of-pocket, try to call the ultrasound location prior to the exam and ask how they prefer to receive payment. 

Finally, in most ultrasound appointments, you are allowed to have one or two people attend with you. This is especially true for pregnancy ultrasounds. However, other diagnostic ultrasounds also tend to allow a guest to emotionally support you during the test. Ask your healthcare provider before your appointment about best practices for your guest(s).


How and when you get your results can vary based on the reason for your test and who is performing it. If you use an electronic program or app that maintains your medical information, you may sometimes see the results show up there before or after your provider contacts you.

With a diagnostic ultrasound, a radiologist (or, a doctor who specializes in medical imaging) will review the images before sending their assessment to your primary care provider. Your provider will then contact you to discuss your results or make a follow-up appointment, if necessary. 

With a pregnancy ultrasound, your sonographer may share your results with you at the end of the appointment or have your primary care provider or obstetrician (a doctor who specializes in pregnancy) give you a call. If you're expecting and have concerns about your ultrasound, there may be a maternal health provider on site that can answer your questions. If there is no provider available on-site, your obstetrician can follow up on your results and discuss them with you in further detail.

Interpreting Your Results 

If your results are positive for the issue or condition your primary care provider was trying to confirm, they may either officially diagnose you and begin treatment or order further testing to get more information. If the results from your ultrasound are negative, you will likely require additional testing to find out what is causing your symptoms. 

Inconclusive results (results that are neither positive nor negative) can lead to several outcomes: your provider may order additional imaging tests or blood work or they may ask you to get a second ultrasound in a few months if the diagnosis isn’t time-sensitive. 

A Quick Review

Sonography is a simple and safe diagnostic imaging process that helps healthcare providers identify and treat several medical conditions, including pregnancy, kidney stones, and tumors. Undergoing sonography may sound scary if you've never experienced one before, but rest assured, this medical imaging test is one of the safest exams available.

There is very little preparation required before going in for an ultrasound. You may have to refrain from eating or drinking before the exam and wear comfortable clothing that is easy to remove. If you have specific questions before, during, or after the exam, talk to your primary care provider or sonographer who will be conducting the test for more information.

Frequently Asked Questions

  • Are a sonogram and an ultrasound the same thing?

    The term “ultrasound” can be used interchangeably with the term “sonography,” but an ultrasound is not the same thing as a sonogram. An ultrasound is the procedure used to capture an image and a sonogram is the image itself. 

  • What's the difference between sonography and radiology?

    Both sonography and radiology are branches of medicine that use diagnostic imaging to diagnose and treat diseases, but they require different types of equipment. Sonography uses high-frequency sound waves to collect images while radiology uses X-ray beams.

  • What doesn't show up during a sonogram?

    There are times when an ultrasound isn’t the best way for your provider to diagnose or evaluate a medical condition. The lungs and bowels can’t be well-studied with an ultrasound, and there are limitations to how far into bone an ultrasound can penetrate. Ultrasounds also can’t differentiate between benign and malignant tumors. 

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8 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Food and Drug Administration. Ultrasound Imaging.

  2. Society of Diagnostic Medical Sonography. Understanding Sonography.

  3. American Registry for Diagnostic Medical Sonography. How to Become a Sonographer.

  4. Radiological Society of North America, Inc. General Ultrasound.

  5. MedlinePlus. Ultrasound.

  6. Ulrich CC, Dewald O. Pregnancy Ultrasound Evaluation. In: StatPearls. StatPearls Publishing; 2023.

  7. American College of Obstetricians and Gynecologists. Ultrasound Exams.

  8. American Cancer Society. Ultrasound for Cancer.

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