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

Prescribed to women with a uterus, progesterone is released into the bloodstream and travels to the organs and tissues where it’s needed. —Bonnie Vengrow, Flow Space, 6 Feb. 2026

Soluble fiber binds to cholesterol and prevents it from being absorbed into the bloodstream. —Jillian Kubala, Health, 5 Feb. 2026

At worst, this leads to rhabdomyolysis, when muscle tissue breaks down and releases proteins into the bloodstream faster than the kidneys can clear them, causing the kidneys to shut down. —Dan England, Outside, 5 Feb. 2026

These particles can lodge deep into lungs and enter the bloodstream. —CBS News, 5 Feb. 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