Health Topic

Genetic Testing

Genetic tests are tests on blood and other tissue to find genetic disorders. Over 2000 tests are available. Read about why you might consider testing.

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Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Genetic Testing

Genetic testing is a type of medical test that looks for changes, sometimes called variants or mutations, in your DNA. DNA contains the genetic instructions in all living things. Often, these changes have no effect, but sometimes, even a small change in DNA can cause disease or other health conditions.

Genetic tests take a sample of your blood or tissues and check your cells to look for any changes in:

  • Genes are parts of DNA found in your cells that carry information that controls what you look like and how your body works. Many genes tell your body how to make proteins, which are needed for your body to work correctly. Genome sequencing is a process that checks all your DNA.
  • Exome sequencing is a process that only checks the parts of your DNA that provide instructions to make proteins.

Most of the time, genetic testing is done through your health care provider. This is called clinical testing. It is done to find out about an inherited disorder (passed down through families) and to help make decisions about your care.

Other ways to get genetic testing include:

  • Research-based testing is a genetic test done as part of a research study (clinical trial).
  • Direct-to-consumer (DTC) testing is a genetic test that allows you to send a DNA sample and get the results. You may do this to learn about your ancestry or your risk for certain diseases.

Genetic testing may be done for many different reasons, including to:

  • Find genetic diseases in a fetus. This is a type of prenatal testing.
  • Screen newborn babies for certain treatable conditions.
  • Lower the risk of genetic diseases in embryos that were created using assisted reproductive technology.
  • Find out if you carry a gene for a certain disease that could be passed on to your children. This is called carrier testing.
  • See whether you are at an increased risk of getting a specific disease. This may be done for a disease that runs in your family.
  • Diagnose certain diseases.
  • Identify genetic changes that may be causing or contributing to a disease that you were already diagnosed with.
  • Help guide your provider in deciding the best medicine and dosage for you. This is called pharmacogenomic testing.
  • To check for, monitor, or manage a disease. This is sometimes used to help find the best cancer treatment.
  • To confirm the biological father (paternity) of a child, or how much genetic information is shared with other relatives.
  • To explore the likelihood of having or developing certain physical traits, such as hair color or facial dimples, or to learn about your ancestry.
  • To help advance our understanding of genetic conditions, learn how genes work, and find unknown genes.

Genetic tests are often done on a blood or cheek swab sample. But they may also be done on samples of hair, saliva, skin, amniotic fluid (the fluid that surrounds a fetus during pregnancy), or other tissue. The sample is sent to a laboratory. There, a lab technician will use one of several different techniques to look for genetic changes.

The benefits of genetic testing include:

  • Helping your provider make recommendations for the management or monitoring of a genetic condition.
  • Giving you more information for making decisions about your health and your family's health: If you find out that you are at risk for a certain disease, you might take steps to lower that risk. For example, you may find out that you should be screened for a disease earlier and more often. Or you might decide to make healthy lifestyle changes.
  • If you find out that you are not at risk for a certain disease, then you can talk to your provider about when it would be appropriate to schedule checkups or screenings.
  • A test could give you information that helps you make decisions about having children.

The physical risks of the different types of genetic testing are small. But there can be emotional, social, or financial drawbacks:

  • Depending on the results, you may feel angry, depressed, anxious, or guilty. This can be especially true if you are diagnosed with a disease that does not have effective treatments.
  • Despite the protections that are in place, you may be worried about genetic discrimination in employment or insurance.
  • Genetic testing may give you limited information about a genetic disease. For example, it cannot tell you whether you will have symptoms, how severe a disease might be, or whether a disease will get worse over time.
  • Genetic testing results might be inconclusive. For example, you might keep getting negative results or not get an answer at all.
  • Some genetic tests may give you results that you didn't expect. For example, if you are tested to check for the cause of a rare disease, and a different variant is found that puts you at increased risk for something else that was previously unknown.
  • Some genetic tests are expensive, and health insurance might only cover part of the cost. Or they may not cover it at all.

The decision about whether to have genetic testing is complex. In addition to discussing the test with your provider, you can meet with a genetic counselor. Genetic counselors have specialized degrees and experience in genetics and counseling. They can help you understand the tests and weigh the risks and benefits. If you do take a test, they can explain the results and make sure that you have the support that you need.

It sits within Pregnancy and Reproduction, Genetics/Birth Defects and Diagnostic Tests.

The lead U.S. institute for this subject is the National Human Genome Research Institute.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Genetic Testing

1,083 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Related Issues

Statistics and Research

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Genetic Testing. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Genetic Testing, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.