blood test

noun

: a test of the blood
specifically : a laboratory test in which a sample of blood is withdrawn from the body to analyze the level of substances or cells (such as glucose, hemoglobin, or white blood cells) that indicate the presence or probable development of a particular disease or medical condition (such as diabetes, cardiovascular disease, or cancer) or serve to indicate the degree of function of a specific organ (such as the liver or kidney)

Examples of blood test in a Sentence

He had a blood test, and the doctor who did it said his cholesterol was too high.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The process has to start with a blood test, ideally ordered by a trichologist or a dermatologist who specializes in scalp and hair who knows what to look for in your results. — Maggie Ryan, Flow Space, 25 Aug. 2026 Instead of using p-tau217 and amyloid blood tests for diagnosis, Isaacson runs them to look for clues on how people are responding to treatment and lifestyle changes. — Sandee Lamotte, CNN Money, 24 Aug. 2026 PrecivityAD2 is a single blood test that quickly assesses the proteins amyloid and tau, using mass spectrometry to measure plasma Aβ42/40 and p-tau217/np-tau217. — New Atlas, 24 Aug. 2026 Stokes describes undergoing blood tests every other week and TMS, or transcranial magnetic stimulation, therapy. — Nicole Fell, HollywoodReporter, 21 Aug. 2026 See All Example Sentences for blood test

Word History

First Known Use

1851, in the meaning defined above

Time Traveler
The first known use of blood test was in 1851

Rhymes for blood test

See All Rhymes for blood test

Browse Nearby Words

blood sugar
blood test
blood thinner
See all Nearby Words

Cite this Entry

“Blood test.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/blood%20test. Accessed 27 Aug. 2026.

Copy Citation

Kids Definition

blood test

noun
: a test of the blood (as to detect the presence of disease-causing agents or determine the number of blood cells)

Medical Definition

blood test

noun
: a laboratory test in which a sample of blood is withdrawn from the body to analyze the level of substances or cells (as glucose, hemoglobin, or white blood cells) that indicate the presence or probable development of a particular disease or medical condition (as diabetes, cardiovascular disease, or cancer) or serve to indicate the degree of function of a specific organ (as the liver or kidney)

More from Merriam-Webster on blood test

Britannica.com: Encyclopedia article about blood test

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of southpaw

See Definitions and Examples »

Popular in Grammar & Usage

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

What's the difference between 'fascism' and 'socialism'?

Commonly Misspelled Words
See More

Popular in Wordplay

See More

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of

Even More Words That Sound Like Insults But Aren't

The Words of the Week - Aug. 28

Why do we say 'break a leg'?
See More

Popular

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
alt-684346df967d5
Add A Letter Quiz Pick the letter that goes in the same spot in fou...
See All