Spit-Up and Vomiting: Telling Them Apart

The short answer

Spit-up and vomiting are two different events, and the difference is mostly about force. The American Academy of Pediatrics describes spitting up as the easy flow of stomach contents out of the mouth, frequently with a burp, and vomiting as the forceful throwing up of stomach contents through the mouth. Those are definitions of two words, not a test for deciding whether a baby needs to be seen. Some findings need help whatever the force, and the bodies below put them on their own urgent and emergency lists. Working out the cause is a clinician's job. Yours is to notice and to call.

When to get help now

Each list below is reproduced as the named body writes it, in its own order and at the tier it sets. Where a list is shortened, this page says so and links to the whole.

NHS (UK), call 999 or go to A&E. From the NHS diarrhoea and vomiting page, all ten bullets in its order:

• vomit blood or have vomit that looks like ground coffee
• have green vomit (adults)
• have yellow-green or green vomit (children)
• may have swallowed something poisonous
• have a stiff neck and pain when looking at bright lights
• have a sudden, severe headache
• have a sudden, severe tummy ache
• have blue, grey, pale or blotchy skin, lips or tongue - on brown or black skin this may be easier to see on the palms of the hands or soles of the feet
• are having severe difficulty breathing, or taking lots of quick, short breaths
• are confused or not responding as usual

Two NHS pages disagree about green or yellow vomit. The reflux in babies page puts it on the lower tier of an urgent GP appointment or NHS 111. The diarrhoea and vomiting page puts it under call 999 or go to A&E. This page uses the more urgent of the two, which is 999.

AAP (US), call your pediatrician immediately. The AAP asks you to be alert for these signs whatever your child's age. All eleven:

• blood or bile (a green-colored material) in the vomit, or vomit that appears to consist of coffee-ground-like material
• severe abdominal pain
• strenuous, repeated vomiting
• swollen or enlarged abdomen
• lethargy or severe irritability
• convulsions
• jaundice
• signs or symptoms of dehydration, including dry mouth, absent tears, depression of the soft spot and decreased urination
• inability to drink adequate amounts of fluid
• vomiting upon waking up
• vomiting that continues beyond 24 hours

NIDDK (US National Institutes of Health), call a doctor right away. All eight:

• crying more than usual or being extremely irritable
• failure to thrive, meaning that an infant or a child weighs less or is gaining less weight than expected for his or her age
• problems breathing
• problems swallowing
• signs of bleeding in the digestive tract, such as vomit that contains blood or looks like coffee grounds, rectal bleeding or stool that contains blood
• signs of dehydration, such as no wet diapers for 3 hours or more, or a lack of energy
• vomiting in large amounts, vomiting that is regularly forceful, also called projectile vomiting, vomiting with bile in the vomit, which makes the vomit green or yellow in color
• vomiting or regurgitation that begins when an infant is younger than age 2 weeks or older than age 6 months

NHS (UK), ask for an urgent GP appointment or get help from NHS 111. From the reflux in babies page, all nine bullets:

• has vomit that's green or yellow, or has blood in it
• is projectile vomiting (being sick with more force than usual)
• has blood in their poo
• has a swollen or tender tummy
• has a very high temperature, or they feel hot, cold or shivery
• keeps being sick and cannot keep fluid down
• has diarrhoea that lasts for over a week or has signs of dehydration
• will not stop crying and is very distressed
• is refusing to feed

The NHS diarrhoea and vomiting page keeps its own call 111 now list at the same tier. All seven bullets, in its order. Two are written for people aged 5 and over:

• you're worried about a baby under 12 months
• your child stops breast or bottle feeding while they're ill
• a child under 5 years has signs of dehydration, such as fewer wet nappies
• you or your child (aged 5 years or over) still have signs of dehydration after using oral rehydration sachets
• you or your child keep being sick and cannot keep fluid down
• you or your child have bloody diarrhoea or bleeding from the bottom
• you or your child have diarrhoea for more than 7 days or vomiting for more than 2 days

Fever. The AAP says that if your baby is 3 months of age or younger and has a rectal temperature of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, call your pediatrician immediately. It gives two further bands: notify the doctor at 101F (38.3C) or greater from 3 to 6 months, and at 103F (39.4C) or higher over 6 months. The NHS high temperature page puts calling 111 at under 3 months with a temperature of 38C or higher, and at 3 to 6 months with 39C or higher.

That same NHS page routes a child with a high temperature to 999 or A&E on any of ten signs. All ten, in its own words, because the recognition cues are the point:

• is drowsy and hard to wake
• is extremely agitated (does not stop crying) or is confused
• has changes to their skin colour such as blue, grey, paler than usual or blotchy skin (this may be harder to see on brown or black skin), or blue, grey or paler than usual lips or tongue
• has difficulty breathing (you may notice grunting noises or their stomach sucking under their ribcage), breathlessness or breathing very fast
• has unusually cold hands and feet
• has a stiff neck
• has a rash that does not fade when you press a glass against it
• is bothered by light
• has a fit (febrile seizure) for the first time (they cannot stop shaking)
• is not responding like they normally do, or is not interested in feeding or normal activities

Duration. The NHS lists vomiting for more than 2 days as a reason to call 111. The AAP lists vomiting that continues beyond 24 hours as a reason to call your pediatrician immediately. The AAP mark is earlier and more urgent, so treat vomiting still going at 24 hours as the point to call.

If you are worried about your baby right now, you do not need a reason that satisfies anyone. Call your pediatrician, your local out-of-hours service, or your emergency number. Trusting your instinct is the correct response.

Why spit-up is so common in the first months

The NIDDK gives the reason. In the first 6 months, it says, infants spend much of their time lying down, do not have a fully developed esophagus and lower esophageal sphincter, and eat meals that are primarily liquid and large relative to their body size. That is gastro-oesophageal reflux, and the NIDDK states plainly that regurgitation and spitting up are normal in infants under 1. It reports that about 70 to 85 percent of infants have daily regurgitation by 2 months, and that most no longer have GER symptoms by 12 to 14 months. The AAP says GER tends to decrease with age but may persist in a mild form until 10 to 12 months. The NHS says reflux usually starts before a baby is 8 weeks old and gets better by the time they are 1.

None of them says spit-up is never worth asking about. Each keeps a list of findings that sit outside it, and those lists are above.

The signs that separate spit-up from vomiting

Force comes first, because that is what the two AAP definitions turn on, and they are quoted at the top of this page. Volume is second, and a source sets the marker rather than a rule of thumb. The NIDDK lists vomiting in large amounts as a reason to see a doctor right away. No source here offers a timing pattern separating ordinary spit-up from vomiting, and this page does not invent one: the AAP's account of pyloric stenosis is forceful vomiting approximately 15 to 30 minutes or less after every feeding. Vomiting soon after a feed is not reassuring.

How the baby is otherwise doing is third, and these are reasons to call, not a screen a baby can pass at home. The NIDDK lists crying more than usual or being extremely irritable, and failure to thrive. The NHS lists not gaining weight, or losing weight, as a reason to see a GP about reflux, and puts refusing to feed, and not stopping crying, on its urgent tier.

Projectile vomiting and what a clinician is ruling out

The NHS describes projectile vomiting as being sick with more force than usual, and puts it on the urgent GP or 111 list. The NIDDK lists regularly forceful, or projectile, vomiting as a reason to see a doctor right away.

One condition clinicians look for in a young baby with this pattern is hypertrophic pyloric stenosis, a thickening of the muscle at the stomach exit that blocks food passing into the intestines. The AAP says it occurs in 1 out of every 500 or so babies, usually starting between 2 and 8 weeks of age, and that babies with it may be hungry still, or again, after vomiting. Its page on infant vomiting gives a wider window, around 2 weeks to 4 months. Great Ormond Street Hospital says it usually develops around six weeks after birth, that a baby may begin by bringing up small amounts of milk after feeding and worsen until no milk stays down, and that the milk may be projected for several feet.

The sources disagree on the age window, which is a good reason not to use age to rule anything out. It is identified by examination and ultrasound, not at home. A baby vomiting forcefully after feeds needs to be seen, at any age.

Green, yellow or bloody vomit

Every source here flags green or yellow vomit, which the NIDDK attributes to bile, and vomit containing blood or looking like coffee grounds. None explains why, so neither does this page. The NIDDK says see a doctor right away and the AAP says call the pediatrician immediately, but act on the most urgent placement: the NHS diarrhoea and vomiting page puts both under call 999 or go to A&E.

Vomiting together with other symptoms

Great Ormond Street Hospital describes intussusception as a condition where the bowel telescopes in on itself, tending to happen between three and 18 months. It says the main symptom is severe abdominal pain that comes and goes, each episode tending to last two to three minutes, that between episodes the child will look very pale, tired and floppy, and that after 12 hours or so the pain becomes more constant, the child usually going off food and possibly vomiting. Their poo may contain blood and mucus. The effects can become serious quite quickly, so it needs emergency treatment.

For ordinary vomiting bugs the NHS says vomiting usually stops in 1 or 2 days, and to call 111 if you are worried about a baby under 12 months.

Sleep and positioning

Reflux does not change safe sleep, and this is one place where getting it wrong has cost lives. The AAP safe sleep page carries fourteen recommendations. Six bear on reflux and are given here. The other eight are on the page linked below. Put your baby on their back for all naps and at night, use a firm, flat sleep surface for sleep, room share rather than bed share, never sleep with your baby, keep soft objects and loose bedding out of your baby's sleep area, and do not let your baby get overheated.

On what firm and flat mean, the AAP writes: "A firm surface means that it shouldn't indent when your baby is lying on it. Any surface that inclines more than 10 degrees isn't safe for your baby to sleep on." The same page states that even babies with gastroesophageal reflux disease should sleep flat on their backs. Other practices exist. This site does not present them as an equivalent option.

If someone has suggested wedges, inclined sleepers, positioners or propping for reflux, take that to your baby's clinician first.

What this page is

This page relays general guidance from named national bodies, and where it shortens a list it says so. The links below go to the whole page. This is not advice about your baby. Anything specific, including feeding changes or any medicine, is a conversation with their own clinician. If you are unsure, the phone call is the right move.

Related baby-care guides

Continue with how often should a newborn feed and safe sleep for babies.

Sources

• Causes of Vomiting in Infants & Children, HealthyChildren.org, AAP, last updated 12/29/2024. Supports the spit-up versus vomiting definitions, the full AAP call-immediately list, the GER persistence statement, the pyloric stenosis mechanism and its 2 weeks to 4 months window, and the 15 to 30 minutes after every feeding sign.
• Hypertrophic Pyloric Stenosis (HPS), HealthyChildren.org, AAP, last updated 10/6/2022. Supports the incidence, the 2 to 8 weeks onset window, hunger still or again after vomiting, and identification by examination and ultrasound.
• Fever and Your Baby, HealthyChildren.org, AAP, last updated 9/23/2025. Supports the AAP threshold for calling immediately about fever in a baby 3 months or younger, and the 3 to 6 month and over 6 month bands.
• A Parent's Guide to Safe Sleep, HealthyChildren.org, AAP, last updated 1/8/2026. Supports the fourteen-recommendation count, the six recommendations quoted here, the firm surface and 10 degree incline definition, and the statement that babies with GERD should sleep flat on their backs.
• Reflux in babies, NHS (UK), last reviewed 10 June 2025. Supports the NHS reflux timeline, the full urgent GP or 111 list, the see-a-GP weight items, and the definition of projectile vomiting.
• Diarrhoea and vomiting, NHS (UK), last reviewed 21 December 2023. Supports the ten-bullet 999 list and the seven-bullet 111 list, both reproduced on the cited page here, and the statement that vomiting usually stops in 1 or 2 days.
• High temperature (fever) in children, NHS (UK), last reviewed 3 January 2024. Supports the NHS 111 temperature thresholds for babies under 3 months and 3 to 6 months, and the 999 list for a child with a high temperature.
• Definition & Facts for GER & GERD in Infants, NIDDK, US National Institutes of Health, reviewed November 2020. Supports the statement that regurgitation and spitting up are normal in infants, the regurgitation prevalence figure, and the resolution age.
• Symptoms & Causes of GER & GERD in Infants, NIDDK, US National Institutes of Health, reviewed November 2020. Supports the full see-a-doctor-right-away list and the account of why reflux is common in the first 6 months.
• Pyloric stenosis, Great Ormond Street Hospital NHS Foundation Trust (UK), no page date shown. Supports onset around six weeks, worsening until no milk stays down, projection of milk for several feet, and ultrasound.
• Intussusception, Great Ormond Street Hospital NHS Foundation Trust (UK), last reviewed 1 August 2016. Supports the definition, the age range, the pain episode pattern, pallor between episodes, the 12 hour change, blood and mucus in the poo, and the need for emergency treatment. This page is the oldest source used here and its date is stated so you can weigh it.

Independent guidance, not medical advice. We do not diagnose or recommend treatments or doses. For any concern about your baby, contact your pediatrician or local emergency service.