bloodstream

noun

blood·​stream ˈbləd-ˌstrēm 

1

: the flowing blood in a circulatory system

2

: a mainstream of power or vitality

… introduce into the economic bloodstream a large amount of money …

—Harper's

Examples of bloodstream in a Sentence

The drug is now entering the bloodstream.

Recent Examples on the Web

Animal studies showed that immune cells sometimes produced antibodies that acted like those rare genetic mutations to prevent folate in the bloodstream from reaching the brain. —Jon Hamilton, NPR, 22 Jan. 2026

The sugar enters your bloodstream, prompting the pancreas to produce insulin, a hormone that moves sugar out of the blood and into the cells for energy. —Kirsten Nunez, Martha Stewart, 21 Jan. 2026

Lamb and Cholesterol Levels Cholesterol refers to the fats in your bloodstream. —Mark Gurarie, Verywell Health, 21 Jan. 2026

The fungus can cause everything from skin infections to life-threatening bloodstream infections, according to the CDC. —Natalie Demaree, Sacbee.com, 20 Jan. 2026

Word History

First Known Use

13th century, in the meaning defined at sense 1

Rhymes for bloodstream

• abeam
• airstream
• daydream
• downstream
• esteem
• extreme
• grapheme
• hakim
• hornbeam
• lexeme
• mainstream
• midstream

Kids Definition

bloodstream

noun

blood·​stream -ˌstrēm 

: the flowing blood in a living thing with a circulatory system

Medical Definition

bloodstream

noun

blood·​stream -ˌstrēm 

: the flowing blood in a circulatory system