The search box appears at the top of every MedlinePlus page.
To search MedlinePlus, type a word or phrase into the search box. Click the Search MedlinePlus button or press the Enter button on your keyboard. The results page shows your first 10 matches. If your search yields more than 10 results, click on Next or page number links on the bottom of the page to view more.
The default display for MedlinePlus searches is a comprehensive list of 'All Results'. Users can focus their search on one part of the site by navigating to an individual collection of results.
Your initial search results show matches from all of the MedlinePlus content areas. The links in the 'Refine by Type' box under 'All Results' represent sets of MedlinePlus content areas, known as collections. The collections help you narrow your search by displaying results exclusively from one collection. For example, you can limit your search results to the latest news by clicking the News link in the 'Refine by Type' box.
MedlinePlus has nine collections:
The 'Refine by Keyword' box organizes your search results into groups based on the most frequent words in the top 200 results. For example, a search on cholesterol might return a cluster of documents that contain the phrase reduce the amount. Clustering helps you narrow down a large set of results quickly to find what you're looking for.
If there is a plus sign () next to a cluster, click on it to view smaller clusters.
If there is a vertical line separating two or more clusters, they have the same number of matches for each term. For example, the earlier search on cholesterol might return a cluster labeled: Diabetes | Blood pressure (5).
Click 'remix' to see additional clusters.
Yes, you can search for a phrase by enclosing words in quotation marks. For example, "health services research" retrieves pages containing that phrase.
Yes, a built-in thesaurus automatically expands your search. The thesaurus contains a list of synonyms from NLM's MeSH® (Medical Subject Headings) and other sources. When there is a match between a search term and a word in the thesaurus, the thesaurus automatically adds the synonym(s) to your search. For example, if you search for the word swelling, results are automatically retrieved for edema.
Yes, you can use the following operators: OR, NOT, -, +, *
You do not need to use AND because the search engine automatically finds resources containing all of your search terms.
|OR||Use when you want either term, but not necessarily both, to appear in the results
Example: Tylenol OR Acetaminophen
|NOT or -||Use when you do not want a particular term to appear in the results
Examples: flu NOT bird or flu -bird
|+||Use when you want the word to appear in your search results exactly as you typed it
Example: +mammogram finds resources containing that exact word; it does not find resources that contain the words mammography or mammoplasty.
|*||Use as a wildcard when you want the search engine to fill in the blank for you; you must enter at least three letters
Example: mammo* finds mammogram, mammography, etc.
Yes, you can restrict your search to a specific site by adding 'site:' and the domain or URL to your search words. For example, if you want to find breast cancer information in MedlinePlus only from the National Cancer Institute, search on breast cancer site:cancer.gov.
The search engine is not case sensitive. The search engine matches words and concepts regardless of capitalization. For example, a search on alzheimer's disease also retrieves pages containing the words Alzheimer's Disease.
You can use special characters in your search, but they're not required. When you use diacritics in your search, the search engine retrieves pages that contain those diacritics. The search engine also retrieves pages that contain the term without special characters. For example, if you search on the word niño, your results include pages that contain the word niño or nino.
Yes, the search engine suggests replacements when it doesn't recognize your search term.
Your search didn't find anything because you spelled a word incorrectly or because the information you're looking for isn't available in MedlinePlus.
If you spelled a word wrong, the search engine consults the thesaurus for a possible match and makes suggestions. If the search engine doesn't give you suggestions, consult a dictionary for the correct spelling. You can try the medical dictionary on MedlinePlus.
If the information you're looking for isn't available on MedlinePlus, you can try searching other resources from the National Library of Medicine. For example, you can search MEDLINE/PubMed, NLM's database of biomedical journal literature.