The National Library of Medicine (NLM) complies with requirements for privacy and security established by the Office of Management and Budget (OMB), Department of Health and Human Services (HHS), and the National Institutes of Health (NIH). This page outlines our privacy and security policy as they apply to our sites as well as third party sites and applications that NLM uses (for example, Facebook and YouTube).
Your Visit to the NLM Websites
Your visit to the NLM websites is private and secure. When you visit the NLM websites, we do not collect any personally identifiable information (PII) about you, unless you choose to explicitly provide it to us. We do, however, collect some data about your visit to our website to help us better understand public use of the site and to make it more useful to visitors. This page describes the information that is automatically collected and stored. NLM never collects information for commercial marketing or any purpose not related to NLM's functions.
What Type of Information NLM Collects
When you visit any website, certain information about your visit can be collected. NLM automatically collects and stores the following type of information about your visit:
- The name of the domain you use to access the Internet (for example, verizon.com, if you are using a Verizon online account, or stanford.edu, if you are connecting from Stanford University's domain)
- The date and time of your visit to our website
- The pages and documents you viewed on our website from an external search engine such as Bing or Google
- The URL of the website you visited prior to ours
- The words you searched for on our website
- The type and version of your Web browser and operating system, and
- Your location at the time of your visit, down to the city-level
This information is used to measure the number of visitors to the various sections of our site and improve organization, coverage, system performance or other problem areas. This information is not used for associating search terms or patterns of site navigation with individual users. When search features offer suggested terms, these suggestions are based on aggregated data only. NLM periodically deletes its web logs. On occasion, NLM may provide aggregated information to third party entities it contracts with for the purposes of research analysis. Aggregated data cannot be linked back to an individual user.
If your electronic medical record (EMR), patient health record (PHR) or other system links you to MedlinePlus, your diagnosis codes or other information, such as medications or procedures names, are sent to our site in order to link you to the most appropriate information. No personally identifiable information is collected in this process.
When you visit any web site, it may place a small text file, known as a "cookie," on your computer. The cookie allows the website to "remember" specific information about your visit while you are connected or when you return to that site. The Office of Management and Budget (OMB) Memo M-10-22, Guidance for Online Use of Web Measurement and Customization Technologies allows Federal agencies to use session and persistent cookies.
The cookie makes it easier for you to use the dynamic features of web pages. Cookies from NLM web pages only collect information about your browser's visit to the site; they do not collect personal information about you. While visiting certain NLM websites, you may occasionally encounter a web page that automatically employs cookies to make it easier to use the web page’s dynamic features.
NLM websites may use either single session (temporary) or multi-session (persistent) cookies. Session cookies last only as long as your web browser is open. Once you close your browser, the cookie disappears. Persistent cookies are stored on your computer for longer periods.
- Session Cookies: We use session cookies for technical purposes such as to enable better navigation through our site. The OMB Memo 10-22 Guidance defines our use of session cookies as "Usage Tier 1 – Single Session." This tier encompasses any use of single session web measurement and customization technologies.
- Persistent Cookies: We use persistent cookies to enhance the web experience for our users. Persistent cookies remain on your computer between visits to NLM until they expire. The OMB Memo 10-22 Guidance defines our use of persistent cookies as "Usage Tier 2 – Multi-session without Personally Identifiable Information (PII)." This tier encompasses any use of multi-session web measurement and customization technologies when no PII is collected.
For example, NLM uses persistent cookies to enable PubMed’s My NCBI feature. The persistent cookie retains user preferences such as search result filters, LinkOut displays, institutional icon links, document delivery services, etc. across user sessions. Users may opt out of the persistent cookie selection in their My NCBI settings at any time. NLM may employ persistent cookies in other ways consistent with our mission and the OMB guidelines to analyze use patterns and improve our users' experience on NLM websites.
How to Opt Out or Disable Cookies
If you do not wish to have session or persistent cookies placed on your computer, you can disable them at any time from your web browser. If you opt out of cookies, you will still have access to all information and resources at NLM, but you may not be able to use cookie-dependent features.
See USA.gov’s Web Measurement and Customization Opt-Out page for instructions on disabling or opting out of cookies in the most popular browsers. Please note when you disable cookies from your web browser, you will disable cookies from all sources, not just those from NLM.
Personally Identifiable Information (PII)
You do not have to give us personal information to visit the NLM website.
If you choose to send us personal information by email, or by filling out a form on our web site, we use this information to respond to your message and to help us provide you with the information or material you requested. If provided, personally identifiable information is maintained in a database that is regularly purged after 410 days.
Third-party contractors employed by NLM may have access to this information in order to provide a response to your question or comment. These contractors are held to strict policies to safeguard the information and provide the same level of privacy protection as guaranteed by NLM.
On occasion, we may conduct a study concerning the types of questions sent to us. These studies help us to improve our websites in order to make them more responsive to the needs of our users.
NLM does not give, share, sell, or transfer any personal information about our visitors, unless required by law enforcement or statute.
Privacy Act Officer
NIH Office of the Senior Official for Privacy (OSOP)
National Institutes of Health, Office of Management Assessment
6011 Executive Blvd., Suite 601, MSC 7669
Rockville, MD 20852
Phone: (301) 496-4606 or (301) 402-6201
Fax: (301) 402-0169
Links from NLM to Other Websites
Visiting an Official NLM Page on Third-Party Websites
NLM maintains accounts on third-party websites, such as social media sites, as tools to better interact with the public. The security and privacy policies of third-party websites apply to your activity on those sites. Users of third-party websites often share information with the general public, user community, and/or the third-party operating the website. You should review the privacy policies of all websites before using them and ensure that you understand how your information may be used. You should also adjust privacy settings of your account for any third-party website to match your preferences.
See the list of NLM’s social media accounts on the Connect with NLM page.
Common third-party website privacy policies used by NLM include:
- Facebook Data Policy
- Instagram Data Policy
How NLM Collects and Uses Information from Third-Party Websites
If you have an account/profile with a third-party website, and choose to follow, like, friend, or comment on a third-party website managed by NLM, certain personal information associated with your account may be made available to us based on the privacy policies of the third-party website and your privacy settings within that website. We do not share personally identifiable information made available through these websites.
NLM conducts and publishes a Privacy Impact Assessment for each use of a third-party website. Each use of a third-party website may have unique features or practices. NLM sometimes collects and uses the information made available through third-party websites.
When you browse through the NLM websites, we use Google Analytics software to gather and temporarily store a variety of information about your visit. However, this information cannot be used to identify you as an individual.
Demographic and Interest Data
On some portions of our website we have enabled Google Analytics and other third-party software (listed below), to provide aggregate demographic and interest data of our visitors. This information cannot be used to identify you as an individual. While these tools are used by some websites to serve advertisements, NLM only uses them to measure demographic data. NLM has no control over advertisements served on other websites.
- Survey tools: NLM also uses surveys to collect opinions and feedback from a random sample of visitors and to understand our visitors’ satisfaction with the NLM website. These surveys do not collect PII and participation is voluntary. If you decline a survey, you will still have access to the identical information and resources on the NLM website as those who take the survey. Answers to surveys help NLM improve its websites to make them easier to use and more responsive to the needs of our visitors. The following privacy policies are available at
Web Measurement and Customization Tools
NLM uses the specified software and features below:
Bit.ly: NLM uses Bit.ly to shorten long URLs for use in email and social media messages.
The U.S. Government maintains this site. For site security purposes and to ensure that this service remains available to all users, we use software programs to monitor traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Causing damage to federal computer systems is a violation of U.S. law and is subject to criminal prosecution in federal court. In the event of authorized law enforcement investigations, and pursuant to any required legal process, information from NLM web logs may be used to help identify an individual.
We encourage and welcome your comments on NLM’s social media properties, including Facebook, Instagram, LinkedIn, Pinterest, YouTube, X, and our blogs. In accordance with the Federal Government's other social media comment policies, NLM has instituted the following policy in an effort to maintain respectful interaction:
- All viewpoints are welcome, but comments should remain relevant to NLM. We respect the varying opinions; however, intentionally spreading misleading or false information is prohibited.
- Personal attacks, profanity, and aggressive behavior are prohibited.
- No spam, advertising, or promoting of products/services. This includes repeated posts of identical or very similar content in a counter-productive manner.
- NLM does not provide medical advice. Please refrain from seeking medical advice.
Comments and/or links will be hidden if they contain:
- Unfair/unsubstantiated partisan political views
- Commercial endorsements
- Discriminatory, racist, offensive, obscene, inflammatory, unlawful, or otherwise objectionable statements, language, or content.
Records of posts and comments will be kept. We reserve the right to block or hide offenders of this policy.
The views expressed in user comments reflect those of the author and do not necessarily reflect the official views of the National Library of Medicine, the National Institutes of Health, or the Federal government.
Linking to a non-federal site does not constitute an endorsement by NLM, NIH, HHS, or any of its employees.
Do not submit copyrighted or other proprietary material in any form unless you clearly indicate that you have permission to do so. By posting your comments or other work, you grant NLM and anyone viewing the NLM website permission to copy, distribute, make derivatives, display or perform the commenter's work publicly and free-of-charge.
Reporters are asked to send questions through their normal channels and to refrain from submitting questions via social media. All media inquiries must be directed to the NLM Office of Communications and Public Liaison at NLMCommunications@nlm.nih.gov.
For help with NLM products and services, please contact the NLM Support Center.
For general information about diseases, conditions, and wellness issues please visit NLM’s MedlinePlus.
Attribution and Rights for Government Works: Works produced by the U.S. government are not subject to copyright protection in the United States. Any such works found on National Library of Medicine (NLM) Web sites may be freely used or reproduced without permission in the U.S. Please acknowledge NLM as the source of the information by including the phrase “Courtesy of the National Library of Medicine” or “Source: National Library of Medicine.”
Copyright Protections for Non-Government Works: When using NLM Web sites, you may encounter documents, illustrations, photographs, or other content contributed by or licensed from private individuals, companies, or organizations that may be protected by U.S. and international copyright laws. You can sometimes tell if content is copyrighted if it has the copyright symbol, the name of the copyright holder, or the statement "All rights reserved." However, a copyright notice is not required by law and therefore not all copyrighted content is necessarily marked in this way.
Transmission or reproduction of copyrighted items (beyond that allowed by fair use as defined in the U.S. copyright laws) requires the written permission of the copyright holders.
NLM Resources with Further Guidance: Some NLM resources also have additional copyright and licensing policies and information, including:
- Copyright Information & Downloading National Library of Medicine Data
- Historical Collections Copyright Information and History of Medicine Division Patron Guide to Copyright and Historical Materials
- MedlinePlus Copyright Information
- National Center for Biotechnology Information (NCBI) Website and Data Usage Policies and Disclaimers
- MedPix® Licensing Information
- PubMed Central (PMC) Copyright Notice
User Responsibility: It is your responsibility to determine and satisfy copyright or other use restrictions when using materials that are not in the public domain. NLM cannot guarantee the copyright status for any item.
Liability: For documents and software available from NLM, the U.S. Government does not warrant or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed.
Endorsement: NLM does not endorse or recommend any commercial products, processes, or services. The views and opinions of authors expressed on NLM Web sites do not necessarily state or reflect those of the U.S. Government, and they may not be used for advertising or product endorsement purposes.
Pop-Up Advertisements: When visiting our Web site, your Web browser may produce pop-up advertisements. These advertisements were most likely produced by other Web sites you visited or by third-party software installed on your computer. The National Library of Medicine does not endorse or recommend products or services for which you may view a pop-up advertisement on your computer screen while visiting our site.
Medical Information: It is not the intention of NLM to provide specific medical advice, but rather to provide users with information to better understand health and disease. Specific medical advice will not be provided, and NLM urges you to consult with a qualified health professional for diagnosis and for answers to your personal medical questions.
Contact the NLM
- If you have concerns relating to copyright, such as improper attribution or NLM using your work without permission, please contact the NLM Support Center.
- If you have concerns relating to History of Medicine content, please see the Historical Collections Copyright Information page.
The NLM logo policy is derived directly from the official logo policies of NIH and HHS, which specify that HHS, NIH, and IC logos may be used only on official communications products that have been created by or for the principal benefit or use of the federal government. The NLM logo and other offering logos may not be used by the private sector, including grantees, vendors, and contractors, regardless of whether the organization is commercial or non-profit.
Along with this, the NLM logo must not appear alongside private sector logos, as this could imply favoritism or endorsement of that particular organization. This holds true even if NLM collaborates with and/or funds in the private sector organization.
Grantees and grantee organizations may not use the NLM logo on any of their communications products (presentations, posters, brochures, websites, etc.) Rather, they should acknowledge NLM funding support through text.
Please use the following language to cite source materials:
Source: National Library of Medicine; National Institutes of Health; U.S. Department of Health and Human Services.
Last Reviewed: October 5, 2023