For adults, vomiting that lasts more than two days warrants a call to your doctor. For children under 2, that window shrinks to 24 hours, and for infants under 12 months, any vomiting that persists should prompt a call within 24 hours. But the calendar isn’t the only thing that matters. Certain warning signs mean you shouldn’t wait at all, regardless of how long you’ve been sick.
General Timelines by Age
The Mayo Clinic sets the standard thresholds most primary care providers follow: two days for adults, one day for children under age 2, and 12 hours for infants. These timelines assume the vomiting is the only significant symptom and that you’re still able to keep some fluids down. If either of those conditions changes, the clock speeds up considerably.
These cutoffs exist because most vomiting is caused by something self-limiting, like a stomach virus or food poisoning. Food poisoning typically resolves within one to three days. A viral stomach bug (norovirus or rotavirus) takes longer, usually three to seven days, though the worst of the vomiting often passes within the first day or two even if nausea lingers. If you’re still actively vomiting past those windows, something else may be going on, and your doctor needs to evaluate it.
Signs You Shouldn’t Wait
Certain symptoms alongside vomiting mean you need care right away, even if you’ve only been sick for a few hours:
- Blood in your vomit, or vomit that looks like coffee grounds or is bright green
- Severe abdominal pain or cramping that persists between episodes of vomiting
- Chest pain
- High fever with a stiff neck
- Confusion, blurred vision, or unusual drowsiness
- Rectal bleeding or black stool
- Fecal smell or material in the vomit, which can signal an intestinal blockage
Any of these combinations calls for an emergency room visit or a call to 911. A severe headache you’ve never experienced before, paired with vomiting, also falls into this category.
Dehydration Changes Everything
The biggest risk from prolonged vomiting isn’t the vomiting itself. It’s dehydration. And dehydration can become dangerous faster than most people expect, especially in very young children and older adults. If you can’t keep fluids down at all, don’t wait for the two-day mark. That alone is reason to call your doctor.
In adults, watch for these signs of dehydration: urinating much less than normal, dark yellow or amber urine, extreme thirst, dizziness when standing, and confusion. A simple skin test can help, too. Pinch the skin on the back of your hand; if it doesn’t flatten back immediately, you’re likely dehydrated.
In infants and young children, the signals look a bit different. No wet diaper for three hours is a red flag. So is crying without tears, a dry mouth, sunken eyes, unusual crankiness or lethargy, and a rapid heartbeat. If a baby’s soft spot on the top of the skull appears sunken, that’s a sign of significant fluid loss.
Timelines for Babies and Young Children
Babies dehydrate quickly because of their small body size, and they can’t tell you how they feel. For infants under 12 months, Seattle Children’s Hospital recommends contacting your doctor within 24 hours for any vomiting, even if the baby otherwise seems okay. If the baby also has a fever above 104°F, stomach pain between vomiting episodes, signs of dehydration, or looks very ill, call right away rather than waiting.
For babies under 12 weeks old with a fever and vomiting, seek care immediately and don’t give any fever medication before being seen. Young infants have immature immune systems, and a fever at that age needs prompt evaluation. If your baby can’t wake up or isn’t moving, call 911.
For toddlers and older children, the 24-hour guideline applies for kids under 2. Children over 2 generally follow closer to the adult timeline, but you should still call sooner if they refuse fluids, seem unusually sleepy, or show signs of dehydration.
Vomiting During Pregnancy
Morning sickness affects most pregnant women and is usually manageable. But when vomiting becomes severe enough that you can’t keep liquids down, you’re producing very little dark urine, or you feel dizzy or faint when standing, contact your OB-GYN. A racing or pounding heartbeat is another signal that dehydration has progressed.
The most severe form of pregnancy-related vomiting, called hyperemesis gravidarum, is typically diagnosed when a woman has lost 5 percent or more of her pre-pregnancy weight along with signs of dehydration. This condition sometimes requires hospital treatment with IV fluids. Don’t assume persistent, severe vomiting is just “normal morning sickness” if it’s preventing you from functioning or keeping any food or water down.
What to Do While You Wait
If your vomiting falls within the “watch and wait” window, the goal is to prevent dehydration while your body fights off whatever’s causing it. Take small, frequent sips of water or an oral rehydration solution rather than trying to drink a full glass at once. If you vomit again after drinking, wait about 20 minutes before trying another small sip. Pushing too much fluid too fast often triggers more vomiting.
Avoid solid food until you can keep clear liquids down consistently. Once you can, start with bland, easy-to-digest foods. Skip dairy, caffeine, alcohol, and fatty or spicy foods until you’ve been vomit-free for several hours.
For children, the same sip-and-wait approach applies. Oral rehydration solutions designed for kids are more effective than water alone because they replace lost salts and sugars. If your child vomits up every attempt at fluids over several hours and can’t keep anything down, that’s a failed rehydration attempt, and it’s time to call the doctor rather than keep trying at home.
When Vomiting Alone Is the Problem
Most stomach bugs cause both vomiting and diarrhea. Vomiting without diarrhea can still be a simple virus, but it also raises the possibility of other causes: a concussion, migraine, appendicitis, intestinal blockage, or a reaction to medication. Clinical guidelines flag “vomiting alone” (without accompanying diarrhea) as something that may need further evaluation beyond standard stomach bug treatment. If you’re vomiting repeatedly with no diarrhea and no obvious explanation like food poisoning, mention that specifically when you call your doctor, as it may change how quickly they want to see you.