flare-up

noun

ˈfler-ˌəp 

1

: a sudden outburst or intensification

a flare-up of hostilities

2

: a sudden bursting (as of a smoldering fire) into flame or light

a danger of flare-ups

3

: a sudden appearance or worsening of the symptoms of a disease or condition

an asthmatic flare-up

Synonyms

• burst
• flare
• flash
• flicker
• flurry
• flutter
• outbreak
• outburst
• spurt

Examples of flare-up in a Sentence

took medication to prevent a flare-up of her asthma

there's no need for an angry flare-up, as we'll take care of the problem immediately

Recent Examples on the Web

Turns out, her life-long eczema and severe flare-ups was in part due to the autoimmune disease, lupus, which she was diagnosed with in 2023. —India Espy-Jones, Essence, 21 Apr. 2025

When symptoms are generally under control and suddenly get worse or more intense, it’s called a flare-up or flare. —Sarah Bradley, Health, 20 Apr. 2025

This filtration system ensures that your floors are getting their most thorough clean, while also ridding your space of irritants like dust that can cause allergy flare-ups. —Terri Williams, Architectural Digest, 18 Apr. 2025

Berenberg also pointed to other risks such as the potential for an unexpected flare-up in the Ukraine war. —Ganesh Rao, CNBC, 11 Apr. 2025

Word History

First Known Use

1839, in the meaning defined at sense 1

Rhymes for flare-up

• buttercup
• backup
• blowup
• breakup
• buildup
• checkup
• cleanup
• holdup
• hookup
• lineup
• lockup
• makeup

Kids Definition

flare-up

noun

ˈfla(ə)r-ˌəp,

ˈfle(ə)r-

: a sudden burst (as of flame or anger)

Medical Definition

flare-up

noun

-ˌəp 

: a sudden appearance or worsening of the symptoms of a disease or condition

an asthmatic flare-up