head ache (headache)

Writers often split compounds that standard English writes as one word: head ache, tooth ache, back ache. Most body-part + ache combinations are closed compounds (headache, toothache, backache, earache, stomachache, heartache). Those extra spaces look careless and can confuse readers.

Quick answer

Write 'headache' as one word. Use a hyphen only when forming a clear modifier (toothache-related); avoid 'head ache' and 'head-ache'.

If the phrase names a single condition or sensation, use the closed form: 'stomachache', not 'stomach ache'.
When it modifies another noun and sounds clumsy, rephrase: 'symptoms from a toothache' or 'toothache-related symptoms'.
If unsure, search your draft for " ache" (space + ache) or check a dictionary.

Core explanation: why 'headache' is one word

Many noun + ache combinations have lexicalized into single words. When a compound denotes a specific, named condition tied to a body part or an emotional state, English usually writes it closed.

Practical test: if the phrase names a condition or familiar sensation, close it up. If it's a literal, novel description, rephrase as 'pain in the X' or check a dictionary.

Closed examples to rely on: headache, toothache, backache, earache, stomachache, heartache.
Avoid nonstandard forms: 'head ache', 'tooth-ache', 'back ache' in formal writing.

Wrong: I can't focus because I have a head ache.
Right: I can't focus because I have a headache.

Spacing vs hyphenation: quick tests and when to rephrase

Compounds appear in three ways: spaced (ice cream), hyphenated (well-known), and closed (headache). Use a dictionary when in doubt. Hyphens usually belong in compound modifiers before a noun, not inside standard -ache nouns.

Decide by function: names of conditions → closed; modifiers that read awkwardly → hyphenate or rephrase; literal descriptions → use 'pain in the X'.

Test 1: Try a single-word synonym. If it fits, the closed form is likely correct.
Test 2: Ask whether the phrase names a condition. If yes → one word.
Modifier tip: prefer 'symptoms from a toothache' to awkward hyphenation.

Wrong: She told HR she was out due to a stomach ache.
Right: She told HR she was out due to a stomachache.
Wrong: He's suffering from a chest ache after the fall.
Right: He's suffering from chest pain after the fall.

Grammar note: compound nouns and modifiers

Compound nouns can be open, hyphenated, or closed depending on usage and lexicalization. Many body-part pain words have shifted to closed forms over time. Hyphens appear mainly when compounds act as adjectives before nouns or when clarity demands them.

Treat 'headache' like any other noun: use 'headache symptoms' or 'symptoms from a headache' instead of inventing 'headache-related' if it reads awkwardly.
Don't write 'tooth-ache' or 'head-ache'-they're nonstandard.

Wrong: We documented head-ache incidents in the report.
Right: We documented headache incidents in the report.

Common -ache compounds to memorize

Memorize the high-frequency closed forms; for less common body parts, prefer 'pain in the X' if the closed form sounds unfamiliar.

High-frequency closed forms: headache, toothache, backache, earache, stomachache, heartache.
Medical note: prefer 'chest pain' to inventing 'chestache'.

Wrong: She called in sick because of a tooth ache.
Right: She called in sick because of a toothache.
Wrong: He complained of a ear ache after the concert.
Right: He complained of an earache after the concert.

Real usage: examples for work, school, and casual contexts

Spelling standards don't change with tone: the closed form works in professional, academic, and casual writing. Below are ready-to-use fixes for each context.

Work (short, professional):

Wrong (email subject): Out sick - severe head acheRight: Out sick - severe headache
Right (status): I'll be remote today; developed a backache after moving equipment.
Right (memo): If employees report backache after the incident, notify HR.

School (concise reporting):

Wrong (note): Ella missed class because of a stomach ache.Right: Ella missed class because of a stomachache.
Right (lab report): The subject reported a headache after exposure to the fumes.
Right (student email): I missed the test because of a toothache; can I reschedule?

Casual (messages and posts):

Wrong (text): Ugh my head ache won't go away.Right: Ugh, my headache won't go away.
Right (chat): I got a backache after that workout.
Right (social post): Heartache is real-take care of yourself.

Try your own sentence and see if the context makes the closed form obvious.

Rewrite help: three direct fixes you can copy

How to fix a split compound: (1) find noun + 'ache' phrases, (2) close them if they name a condition, (3) if they sound awkward, rephrase as 'pain from a X' or use a short hyphenated modifier.

Rewrite 1: Original: 'I have a terrible head ache so I will not go to work.'
Rewrite: 'I have a terrible headache, so I won't come into work.'
Rewrite 2: Original: 'She told the teacher she had a tooth ache and missed the test.'
Rewrite: 'She missed the test because of a toothache.'
Rewrite 3: Original: 'After lifting boxes he felt back ache and couldn't finish the shift.'
Rewrite: 'After lifting boxes, he developed a backache and couldn't finish his shift.'

Examples: quick wrong/right pairs and short fixes

Search-and-replace patterns you can use across a document.

Wrong: 'head ache' →
Right: 'headache'
Wrong: 'tooth ache' →
Right: 'toothache'
Wrong: 'back ache' →
Right: 'backache'
Wrong: 'ear ache' →
Right: 'earache'
Wrong: 'stomach ache' →
Right: 'stomachache'
Wrong: 'heart ache' →
Right: 'heartache'
Wrong: 'tooth-ache symptoms' →
Right: 'toothache symptoms' or 'symptoms from a toothache'
Wrong: 'head-ache incidents' →
Right: 'headache incidents'

Memory tricks and quick proofreading checks

Mnemonic: say pain words as one unit-'headache', 'toothache', 'backache'. That mental chunk helps avoid splits.

Proofreading tips: search your document for " ache" (space + ache), run a spell/grammar check, and add common closed -ache words to autocorrect or your cheat sheet.

Add the six common closed forms to your personal checklist.
Use whole-word replacements in your editor to fix 'head ache' → 'headache' across a document.

Similar mistakes to watch for

Once you fix 'head ache', check for other compound errors: everyday/every day, a lot/alot, all right/alright, and adjective compounds that need hyphens before nouns.

everyday (adj) vs every day (phrase)
a lot (two words)-never 'alot'
all right (preferred) vs alright (informal)
Prefer 'chest pain' to inventing 'chestache'.

Wrong: 'She wears a everyday coat.' →
Right: 'She wears an everyday coat.'
Note: 'alright' is informal; prefer 'all right' in formal writing.
Wrong: 'He had chest ache' →
Right: 'He had chest pain.'

FAQ

Is 'head ache' ever correct?

Not in standard written English. Use 'headache' as one word. 'Head ache' might appear in casual texting or poetic phrasing, but avoid it in professional and academic contexts.

Should I write 'heartache' or 'heart ache'?

Write 'heartache' as one word. It is a standard closed compound for emotional pain.

When should I use a hyphen with '-ache' words?

Rarely hyphenate inside the -ache word itself. Use hyphens when you need a compact modifier before a noun (e.g., 'toothache-related symptoms') but consider rephrasing for clarity.

How can I quickly find spacing errors like 'head ache' in my document?

Search for " ache" (space + ache) in your editor, run a grammar check, or enable spelling suggestions. Many tools will recommend the closed form.

Is 'backache' appropriate in medical writing?

'Backache' is an acceptable, neutral noun in everyday and many clinical contexts. For precise clinical descriptions, 'back pain' may be preferred depending on specificity required.

Still unsure about a sentence?

Paste the sentence into a dictionary or grammar tool to check closed compounds and hyphenation. Searching for " ache" across a document quickly finds common spacing errors.

If you want, copy one problematic sentence and check how it reads after applying these fixes.