Privacy Policy

The National Library of Medicine (NLM) offers this website as a public service. We do not collect any personally identifiable information (PII) about you when you visit our Web sites, unless you decide to provide us with such information. We collect information about your visit to our website to help us better understand how the public uses the site and how to make it more useful. NLM never collects information for commercial purposes or for any purpose that is not related to the functions of NLM.

Type of Information Collected

When you visit any website, some information about your visit is collected. NLM collects and automatically stores this information about your visit:

  • Internet address and the domain from which you are visiting the NLM website
  • Information about the operating system and browser used
  • Date and time of your visit
  • Pages Visited
  • Internet address of the website that connected you to the NLM site
  • Words sought

This information is used to measure the number of visitors to the different sections of our site and to improve the organization, coverage, system performance or problem areas. This information is not used to associate search terms or site navigation patterns with individual users. When search functions can suggest terms, these suggestions are based only on aggregate data. NLM periodically deletes Web logs. In some cases, NLM may provide aggregated information to contracted third parties for research analysis. The aggregate data can not be linked back to an individual user.

If your electronic health record (EMR), health records (PHR) or other system links you to MedlinePlus, its diagnostic codes or other information such as medications or procedures, you are sent to our site to link it to you with most information relevant. No identifiable information is collected in this process. We may review the information in order to improve our site and better meet the needs of users, but this information is reviewed at the aggregate level.


When you visit any website, you can 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 online or when you return to that site. The note from the Office of Management and Budget (MMO) M-10-22, Guide for Online Use of Web Measures and Customization Technologies (PDF *, 1.03MB), 6/25/2010, Enables federal agencies Use persistent and session cookies as Defined below.

The cookie facilitates the use of the dynamic functions of web pages. The cookies on the NLM Web pages only collect information about your browser’s visit to the site, we do not collect your personal information. During your visit to certain NLM sites, from time to time you may find a Web page that uses cookies automatically to facilitate the use of the dynamic features of these web pages.

NLM Web sites may use single (temporary) or multiple (persistent) session cookies. Session cookies only last while your 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, for example, to allow better navigation through our site. WMO note 10-22 defines the use of session cookies as “Usage Level 1 – Single Session”. This covers any use of single session metering and personalization technologies.

Persistent Cookies: NLM uses persistent cookies to improve our users’ web experience. Persistent cookies remain on your computer on your NLM visits until they expire. The WB 10-22 memo defines the use of persistent cookies as “Usage Level 2 – Multiple Session Without Personally Identifiable Information (PII)”. This level covers any use of multisession personalization and measurement technologies in which PII is not compiled.

For example, NLM uses persistent cookies to enhance the function of the PubMed retrieval system called “MyNCBI”. The persistent cookie preserves user preferences such as filters for results, samples of LinkOut, links to institutional icons, information delivery services, etc.

How to disable cookies

If you do not want to have session or persistent cookies on your computer, you can disable them at any time from your Internet browser. If you disable cookies, you still have access to all the information and resources of the NLM, but you may not be able to use the cookie-dependent features. Follow these instructions to disable or disable cookies in the most popular browsers, Please note that by disabling cookies in your Web browser, you will disable cookies from all sources, not just those from the NLM.

Personally Identifiable Information (PII)

If you choose to provide us with personal information by sending an email or completing a form with your personal information and sending it through our website, we will use that information to respond to your message and to provide you with the information or material you have requested.

If provided, personally identifiable information is kept in a database that is regularly deleted. Companies hired by NLM may have access to this information to provide an initial response to your question or observation. NLM maintains its contractors under strict policies to protect the information and provide the same level of privacy protection guaranteed by NLM. From time to time, we could conduct a study of the types of questions sent. These studies help us improve our Internet portals to make them more receptive to the needs of our users. We do not supply, share, sell or transfer personal information to third parties unless required by law.

Links to other portals

Some NLM Internet portals, such as MedlinePlus, provide links to other websites that provide health information. Once you access another website, you are subject to the new portal privacy policy.


The United States Government maintains this page. For security reasons of the portal and to ensure that this service remains available to all users, we use computer programs to monitor traffic to identify unauthorized attempts to download files or change information or otherwise cause harm. Cause damage to federal computer systems is a violation of US law and is subject to criminal prosecution in federal court. In the case of authorized investigations for law enforcement and in accordance with any necessary legal process, information from these sources may be used to help identify an individual.

Third-party websites and apps

Third-party websites and applications are web technologies that are not operated or controlled by the US National Library of Medicine. UU. (NLM). They can be hosted on a non-governmental website or embedded in an NLM page. These technologies can make personally identifiable information (PII) available to NLM, regardless of whether we require it or collect it. In addition, other official government websites of which we provide links or with which we cooperate may use a third party to handle some aspects of the collection of information (for example, the contest nomination process). As a result, our privacy / notice policy may not apply.

We use technologies to communicate and interact with you. Examples are social media sites like Twitter and Facebook. The activity on these non-governmental websites is governed by the security and privacy policies of those sites. When you use them, you are generally sharing information with the general public and other users and / or the group that operates that site or that application. We suggest that you review the privacy policies of these sites before using them to ensure that you understand how these third-party sites and applications may use your personal information. You may be able to adjust the privacy settings of your account.

The following list includes the applications we use and their purposes. For sites or applications that collect personally identifiable information, this list also includes details about the information we collect and how NLM protects your private information.


NLM has several pages on Facebook where it shares news, activities, programs and other issues that may be of interest to you. You do not need to register or provide personal information to view our Facebook pages. The full list of NLM Facebook pages can be found at


NLM uses GovDelivery to manage email subscriptions for its e-newsletters, e-mail alerts and other messages about NLM products and services. To subscribe to GovDelivery to receive updates on NLM products and services, you must provide an email address and indicate your subscription preferences, including the NLM products and the type of updates you would like to receive.

GovDelivery collects unidentifiable information about the number of messages sent, how often people open e-mail messages and whether they click on the message links. This information is provided to NLM administrators on the GovDelivery website that is password protected. It is only available to NLM administrators and staff that handles email subscription lists as part of their functions.

Google Analytics Premium

NLM uses Google Analytics Premium. Please see the following policies on the Google website for more information:

  • Google’s top privacy policy
  • Cookies and Google Analytics for Websites
  • Disable Google Analytics cookies

ITunes App Store

NLM uses iTunes to make iPhone, iPod and iPad applications available for download through the Apple App Store. A list of NLM applications is available at You do not need to register or provide personal information to view the NLM applications in the App Store. If you use the iTunes program to view information about NLM applications, iTunes collects the information specified in your privacy policy.

If you have an iTunes account and download an application, you can evaluate or make an app review. If you evaluate an application, your personally identifiable information may be viewed by other iTunes users, including NLM staff. The amount of personally identifiable information will depend on your account settings. To avoid displaying your personally identifiable information, you should not create an account in iTunes, download applications, or write an evaluation.

NLM does not collect, maintain, disclose or share any information about people downloading NLM applications. Apple collects and provides non-personally identifiable information about how many times an application has been downloaded and from which continent. This information is password protected and is only available to NLM administrators and iTunes application administrators who require this information as part of their functions. The iTunes privacy policy is available at


NLM uses Twitter to send concise messages (up to 140 characters), also called “Tweets”, to share information about NLM, activities, programs and other issues that may be of interest to you. We also respond to comments and questions sent to NLM via Twitter. You do not need to register or provide personal information to view our pages on Twitter. The full list of NLM feeds on Twitter can be found at

If you want to subscribe to (also called “Follow”) NLM feeds on Twitter, you can create a Twitter account at To create an account, you must provide your name and email address and create a username and password. You can include additional information such as a short biography, location and photo. Most of your personal information on your Twitter account is publicly available unless you have updated your privacy settings.

NLM staff monitors the number of subscribers (called “Followers”) and responds to their comments and concerns through Twitter, but does not collect, store, share or share any information about people following NLM on Twitter. Twitter’s privacy policy is available at