13 Common Idioms for Being Sick: Meanings and Examples

Understanding idioms for being sick can transform how you express illness in English, whether you’re chatting with friends or writing an email to your boss. These colorful phrases appear constantly in everyday conversation, movies, and books. This post breaks down 13 of the most common sickness idioms, explains their origins, and shows you how to use them naturally.

You’ll learn what each one really means, when to say it, and how to avoid embarrassing mistakes.

Simply put, these 13 idioms for being sick cover everything from mild fatigue to serious illness. Each one carries a distinct tone and level of severity. Master them, and you’ll sound like a native speaker when describing how you feel.

Key Takeaways

• Idioms for being sick range from mild (“under the weather”) to severe (“at death’s door”), so context matters.
• Most sickness idioms have historical origins tied to sailing, boxing, or old medical practices.
• Using idioms for being sick correctly makes your English sound natural and expressive in both casual and professional settings.
• Many of these phrases work for both physical illness and general exhaustion or burnout.
• The best approach is to learn a few at a time and practice them in real conversations.

1. Under the Weather – Feeling Slightly Unwell

“Under the weather” is the most common and versatile idiom for feeling mildly sick. You use it when you have a cold, a headache, or just feel a bit off but can still function. It’s polite enough for work emails and casual enough for text messages to friends.

The phrase likely comes from sailing. When a sailor was feeling sick, they were sent below deck, under the weather, to recover from rough seas. Over time, it evolved to mean any minor illness.

• Use it for mild illnesses: colds, headaches, allergies, fatigue
• Works in professional settings: “I’m feeling under the weather today, so I’ll work from home”
• Can describe emotional or mental exhaustion, not just physical sickness
• Never use it for serious or life-threatening conditions
• Often paired with “a bit” or “slightly” to soften the meaning

Tip: Pair “under the weather” with “a bit” or “slightly” to sound more natural: “I’m feeling a bit under the weather this morning.”

Best For: Everyday conversations about minor illnesses, sick day requests, and polite excuses.

2. Come Down With Something – Starting to Feel Sick

“Come down with something” describes the moment you start feeling symptoms of an illness. It’s the idiom you use when you’re not sure what you have yet, but you know something’s wrong. The phrase suggests the illness is “coming down” on you like rain or weather.

You’ll hear this constantly in British and American English alike. It’s slightly more informal than “under the weather” but still perfectly acceptable in most workplaces.

• Use it when symptoms first appear, not when you’re fully sick
• Often followed by specific illnesses: “I think I’m coming down with a cold”
• Can be used with “something” as a catch-all: “She’s coming down with something”
• Works in past tense too: “I came down with the flu last week”
• Common collocations: “coming down with a cold,” “coming down with the flu,” “coming down with a bug”

According to the Cambridge Dictionary, this phrase appears in everyday British English more frequently than any other sickness idiom, making it essential for learners.

Best For: Describing the early stages of illness, especially when you can’t name the exact sickness yet.

3. Sick as a Dog – Extremely Ill

“Sick as a dog” means very sick, usually with nausea, vomiting, or a severe stomach bug. Unlike “under the weather,” this idiom signals that you’re genuinely miserable. The phrase has been around since at least the 1700s, though the exact reason dogs are referenced remains unclear.

Some say it’s because dogs would eat anything and get sick; others think it refers to how pitiful a sick dog looks.

This one is informal and vivid. You wouldn’t use it in a formal email to your boss, but it’s perfect for texting friends or explaining why you canceled plans.

Expression	Severity Level	Formality
Under the weather	Mild	Formal/Informal
Sick as a dog	Severe	Informal only
At death’s door	Extreme	Informal/Hyperbolic

This table shows how the idioms differ in severity. “Sick as a dog” sits firmly in the severe category, so use it when you’re really suffering, not just tired.

Best For: Dramatic, humorous descriptions of being very ill, especially with stomach issues or food poisoning.

4. Feel Like Death Warmed Up – Absolutely Terrible

“Feel like death warmed up” (or “death warmed over” in American English) means you feel absolutely awful. It’s a hyperbolic idiom that paints a vivid you look and feel as terrible as someone who’s been through a serious ordeal. The “warmed up” part adds a darkly humorous twist, suggesting you’re barely alive but somehow functioning.

This phrase is dramatic and expressive. Native speakers use it when they want to emphasize just how terrible they feel, often with a hint of humor. It’s informal and best saved for close friends or family.

The Oxford English Dictionary traces this idiom to the early 20th century, with usage concentrated in British and Australian English. It’s less common in American speech, where “death warmed over” is the preferred version.

1. Use it for extreme exhaustion, severe flu, or hangovers
2. Add “absolutely” for emphasis: “I feel absolutely like death warmed up”
3. Pair it with “look” to comment on someone’s appearance: “You look like death warmed up”
4. Reserve for informal settings only
5. Expect a sympathetic or amused reaction from native speakers

Warning: Don’t say this to someone who’s actually seriously ill. It can come across as insensitive or mocking. Save it for mild-but-miserable situations.

Best For: Describing extreme exhaustion, hangovers, or severe flu in a humorous, exaggerated way.

5. Out of Sorts – Feeling Off and Unsettled

“Out of sorts” describes a general feeling of being unwell, grumpy, or just not yourself. It’s vaguer than other idioms because it covers both physical and emotional discomfort. You might feel out of sorts after a bad night’s sleep, during a stressful week, or when a mild cold is coming on.

The phrase dates back to the 1600s and originally referred to printing, where “sorts” were individual letters. When a printer ran out of letters, they were literally “out of sorts.” The meaning shifted over time to describe anyone feeling unsettled.

• Covers both physical and emotional discomfort
• More common in British English than American
• Often used with “feeling” or “feels”: “I’ve been feeling out of sorts all day”
• Can describe someone who’s unusually grumpy or irritable
• Works for both short-term and longer-lasting moods

Best For: Describing a vague sense of being unwell or emotionally off that you can’t quite pinpoint.

6. Laid Up – Confined to Bed or Unable to Move

“Laid up” means you’re stuck in bed or unable to do your normal activities because of illness or injury. It comes from the nautical world, where ships were “laid up” in port when they needed repairs. Similarly, when you’re laid up, your body needs time to recover.

This idiom is particularly useful because it covers both illness and injury. You can be laid up with the flu, a broken leg, or after surgery. It implies a longer recovery period than “under the weather.”

According to Merriam-Webster, the phrase has been in use since the late 1700s and remains common in both British and American English today.

Scenario	Correct Idiom	Example
Minor cold	Under the weather	“I’m a bit under the weather.”
Broken leg	Laid up	“I’m laid up with a broken leg.”
Food poisoning	Sick as a dog	“I was sick as a dog all night.”

Best For: Describing longer-term illness, recovery from surgery, or injuries that keep you home.

7. Run Down – Exhausted and Vulnerable to Illness

“Run down” describes a state of exhaustion that makes you vulnerable to getting sick. When you’re run down, you’ve been pushing yourself too hard. You haven’t slept enough, you’ve been stressed, and your body is telling you to slow down.

This idiom is both a physical and mental state.

It’s different from “under the weather” because it describes the cause, not just the symptom. You feel run down because of overwork or stress, and that’s why you catch every cold going around.

• Describes chronic exhaustion rather than acute illness
• Often precedes getting actually sick
• Can be used as an adjective: “I feel so run down lately”
• Related to the verb “to run someone down” (to exhaust someone)
• Common in workplace conversations about burnout

The British Council lists “run down” among the top 50 idioms English learners should know, noting its frequency in workplace communication.

Important: “Run down” can also mean “to criticize” or “to hit with a vehicle.” Context is key. When talking about health, it almost always means exhausted.

Best For: Explaining why you keep getting sick or describing work-related exhaustion.

8. Green Around the Gills – Looking Pale and Nauseous

“Green around the gills” describes someone who looks pale, queasy, or about to vomit. The “gills” reference comes from fish, which appear greenish around their gills when unhealthy. It’s a visual idiom, meaning you use it when commenting on someone’s appearance rather than describing your own feelings.

This phrase is more common in British English but understood everywhere. It’s slightly old-fashioned, which makes it charming when used correctly. You might hear it in a hospital, on a boat, or at an amusement park after a roller coaster ride.

1. Use it to comment on someone’s appearance: “You look a bit green around the gills”
2. Works for seasickness, food poisoning, or hangovers
3. Can be shortened to just “green around the gills” without extra words
4. Often preceded by “a bit” or “slightly”
5. More common in the UK and Australia than in the US

Best For: Commenting on someone who looks nauseous or pale, especially in humorous or concerned contexts.

9. Off Color – Feeling Slightly Unwell or Looking Pale

“Off color” (or “off-colour” in British spelling) means feeling slightly unwell or looking paler than usual. It’s a mild, polite way to say someone doesn’t look well. The phrase comes from the idea of something being slightly discolored, not quite its normal healthy shade.

In British English, “off color” can also mean a joke or comment that’s slightly inappropriate or rude. This dual meaning makes context essential. When talking about health, it always refers to feeling unwell.

According to Collins Dictionary, this idiom has been in continuous use since the early 1800s and remains a staple of polite British conversation about health.

• Milder than “green around the gills”
• Often used about children: “She’s a bit off color today”
• Can describe both appearance and feeling
• More common in British English
• Works for vague, hard-to-describe illnesses

Best For: Polite, vague descriptions of someone feeling slightly unwell, especially children or colleagues.

10. At Death’s Door – Very Seriously Ill

“At death’s door” describes someone who is extremely ill, close to dying. In modern usage, it’s almost always hyperbolic, meaning people say it when they’re very sick but not actually dying. The phrase has been used since medieval times and appears in literature throughout the centuries.

You need to be careful with this one. It’s dramatic and can sound alarming if taken literally. Native speakers use it with a wink, acknowledging the exaggeration.

If someone says “I felt like I was at death’s door,” they usually mean they had a terrible flu, not that they were hospitalized.

The Cambridge English Corpus shows that this idiom appears most frequently in informal conversations and humorous contexts, rarely in medical or professional settings.

Warning: Avoid this phrase when someone is genuinely critically ill. It can seem dismissive or insensitive. Use it only for exaggerated, humorous descriptions of your own illness.

Best For: Exaggerated, humorous descriptions of severe illness that isn’t actually life-threatening.

11. Down for the Count – Completely Incapacitated

“Down for the count” comes from boxing. When a boxer is knocked down and can’t get up before the referee counts to ten, they’re “down for the count.” In everyday usage, it means you’re completely unable to function because of illness, exhaustion, or injury.

This idiom is more energetic and visual than others on this list. It implies a sudden collapse, not a gradual decline. You might say you were “down for the count” after a bout of food poisoning or a particularly brutal flu.

• Implies sudden, complete incapacitation
• Can describe physical illness or extreme exhaustion
• Often used in past tense: “I was down for the count for three days”
• Also used figuratively for non-health situations
• Has a slightly dramatic, sports-like tone

Best For: Describing being completely knocked out by illness, especially after a sudden onset.

12. Peaked – Looking Pale and Unwell

“Peaked” (pronounced “pea-ked”) describes someone who looks pale, thin, or unwell. It’s a visual idiom you use to comment on appearance. Someone who is peaked looks like they haven’t been eating well, sleeping enough, or recovering from an illness.

This word is more common in American English, particularly in the South and Midwest. It’s often used about children who look unwell or adults who are recovering from sickness. The exact origin is debated, but it likely comes from the idea of someone looking “peaked” like the point of a mountain, sharp and drawn.

The American Dialect Society notes that “peaked” has been part of American regional speech since the early 1900s, with usage concentrated in rural communities.

1. Always describes appearance, not how someone feels
2. Often used with “look” or “looking”: “You’re looking a bit peaked”
3. More common in American English than British
4. Can describe someone recovering from illness
5. Often paired with “pale” for emphasis

Best For: Commenting that someone looks unwell or pale, especially after an illness.

13. The Creeping Crud – A Vague, Unpleasant Illness

“The creeping crud” is a humorous, informal idiom for a vague, unpleasant illness that you can’t quite identify. It’s the kind of thing you say when you have a mysterious bug that makes you feel awful but doesn’t have clear symptoms. The phrase has a playful, almost childish quality to it.

This idiom is more common in American English, particularly among older generations. It’s the kind of phrase a grandparent might use to describe why they’re not feeling well today. It’s not offensive or crude despite the word “crud,” which here means something unpleasant or worthless.

• Perfect for mysterious, hard-to-describe illnesses
• Has a humorous, lighthearted tone
• More common in American English
• Often used with “the”: “I’ve got the creeping crud”
• Never used for serious or specific medical conditions

Tip: Use “the creeping crud” when you want to make light of being sick. It’s a great icebreaker because it almost always gets a laugh.

Best For: Humorous descriptions of vague, annoying illnesses that you can’t quite name.

Frequently Asked Questions

What is the most common idiom for being sick?

“Under the weather” is the most widely used idiom for being sick in both British and American English. It’s mild, polite, and appropriate for nearly any situation, from casual conversations to professional emails. The Cambridge English Corpus consistently ranks it as the most frequent sickness idiom in everyday speech.

Can I use these idioms for being sick in professional settings?

Yes, but choose carefully. “Under the weather” and “coming down with something” are safe for work emails and professional conversations. “Sick as a dog,” “feel like death warmed up,” and “the creeping crud” are too informal for professional settings.

When in doubt, stick to the milder idioms.

What’s the difference between “under the weather” and “sick as a dog”?

“Under the weather” describes mild illness, like a slight cold or headache. “Sick as a dog” describes severe illness, usually with nausea or vomiting. Think of it as a spectrum: “under the weather” is a 2 out of 10 on the sickness scale, while “sick as a dog” is an 8 or 9.

Are these idioms for being sick used in American or British English?

Most of these idioms work in both American and British English, but a few have regional preferences. “Off color” and “peaked” are more common in British English, while “the creeping crud” and “death warmed over” are American. “Feel like death warmed up” is more British and Australian.

How can I remember these idioms for being sick?

Group them by severity. Learn the mild ones together (“under the weather,” “off color,” “out of sorts”), then the moderate ones (“come down with,” “run down,” “laid up”), and finally the severe ones (“sick as a dog,” “at death’s door,” “down for the count”). Practice using one or two in real conversations each week.

Final Thoughts

These 13 idioms for being sick give you a rich vocabulary for describing illness in English. Start with “under the weather” and “come down with something,” then expand from there. The more you practice, the more natural these phrases will feel in your everyday speech.