Signs of serious illness in children — when to worry.

Most childhood illnesses can be cared for at home. This guide helps you tell the difference between a child who is “regular sick” and one who needs medical care today — or right now. How your child looks and acts usually matters more than any single number, including the temperature.

Last updated: September 2026 For children ages 0–5
If your child is struggling to breathe, turning blue or gray, can’t be woken up, or is having a seizure, call 911 now.

Three levels of sick

Use these as a guide. If your child falls between two levels, choose the higher one.

Usually OK to care for at home

  • Makes eye contact and responds to you
  • Can be comforted when upset
  • Drinking, even if less than usual
  • Has moments of playing or interest
  • Sleeps more but wakes easily
  • Normal skin color

Watch closely. Call your doctor with questions.

Call your doctor today

  • Much fussier or sleepier than normal
  • Drinking poorly or peeing less
  • Breathing faster than normal
  • Fever that lasts longer than expected (see Fever below)
  • Pain that isn’t getting better
  • Just “not right,” and you can’t say why

Call your child’s doctor or nurse line. Your child may need to be seen.

Get emergency care now

  • Severe trouble breathing, or breathing pauses
  • Blue, gray, or very pale lips or skin
  • Limp, floppy, or very hard to wake
  • Seizure
  • Stiff neck with fever
  • Severe dehydration or inconsolable pain

Call 911 or go to the emergency room.

What emergency teams look at first

Pediatric emergency clinicians often start with three quick checks: how a child looks, how hard they’re breathing, and their color. You can do the same checks at home.

Appearance

Reassuring

  • Alert, looks at you, responds to your voice
  • Can be comforted
  • Acts like themselves between fevers

Concerning

  • Limp, floppy, or listless
  • Blank stare, won’t make eye contact
  • Crying that won’t stop, or confused

Work of breathing

Reassuring

  • Quiet, easy breathing
  • Can feed, cry, or talk normally

Concerning

  • Fast breathing, grunting, or nostrils flaring
  • Skin pulling in between or under the ribs
  • Squeaky or whistling sounds
  • Babies stopping feeds to breathe

Circulation and color

Reassuring

  • Normal color for your child’s skin tone
  • Warm hands and feet
  • Peeing normally

Concerning

  • Blue, gray, or blotchy skin or lips
  • Cold, clammy hands and feet
  • Very little or no pee

MamaBear tip: Check color inside the lips, on the gums, and in the nail beds. These are easier to read than skin on every skin tone. See our Difficulty Breathing guide for photos and a breathing-rate tool.

Warning signs by symptom

Tap a topic to see when to call the doctor and when to get emergency care.

Breathing

Emergency care now:

  • Struggling to breathe, gasping, or breathing pauses
  • Blue or gray lips, tongue, or face
  • Deep pulling-in of the skin at the ribs, neck, or belly
  • High-pitched squeaky sound when breathing in while calm (stridor)
  • Drooling or unable to swallow

Call your doctor today:

  • New or worsening wheezing
  • Breathing faster than normal, or mild pulling-in at the ribs
  • Cough with fever that isn’t improving

More detail: Difficulty breathing — what to look for.

Fever

Fever itself is usually not dangerous — it’s the body fighting infection. A temperature of 100.4°F (38.0°C) or higher is a fever. For babies and toddlers, a rectal temperature is most accurate.

Your childWhat to do
Younger than 3 months with 100.4°F (38.0°C) or higherCall the doctor right away, day or night. Young babies need to be checked quickly.
Any age, temperature repeatedly above 104°F (40°C)Call the doctor right away.
Younger than 2 years, fever lasting more than 24 hoursCall the doctor.
2 years or older, fever lasting more than 3 daysCall the doctor.
Fever with a stiff neck, severe headache, trouble breathing, a rash that doesn’t fade when pressed, a seizure, or looks very illGet medical care right away.
Fever with a chronic condition (heart problems, weak immune system, sickle cell disease, or steroid medicines)Call the doctor right away.

It’s a good sign if your child plays and interacts once a fever-reducer takes effect. Call if your child still acts sick after the fever comes down, or seems to be getting worse.

Medicine safety: Don’t give ibuprofen to babies younger than 6 months, and never give aspirin to children. Dose by weight — see our medication dosage calculator — and ask your pediatrician or pharmacist for the correct dose if your child is younger than 2.

Dehydration (not drinking, vomiting, or diarrhea)

Emergency care now:

  • Very sleepy, weak, or hard to wake
  • Sunken eyes, and no tears when crying
  • Cool, blotchy hands and feet, or fast breathing

Call your doctor right away:

  • No pee in 8 hours, or only small amounts of dark pee
  • Babies: fewer than 6 wet diapers in a day
  • Dry, sticky mouth, or a sunken soft spot on a baby’s head
  • Can’t keep any fluids down
  • Vomit that is green or contains blood, or bloody diarrhea
Sleepiness, seizures, and behavior changes

Emergency care now (call 911):

  • Can’t be woken, or doesn’t respond to your voice or touch
  • A seizure lasting longer than 5 minutes, repeated seizures, or not returning to normal afterward
  • A first-ever seizure
  • Stiff neck, especially with fever
  • Suddenly can’t move an arm or leg, or one side of the face droops
  • Very confused, or doesn’t recognize you

Call your doctor today:

  • Unusually sleepy but can be woken
  • Headache that won’t go away (older children)
Rash and allergic reactions

Emergency care now:

  • Purple or red spots that don’t fade when you press a clear glass against them — especially with fever
  • Swelling of the lips, tongue, or face, trouble breathing or swallowing, or repeated vomiting after a known allergen. If your child has prescribed epinephrine, use it first, then call 911. Antihistamines don’t treat severe reactions and shouldn’t delay epinephrine.
  • Blistering or peeling skin that spreads quickly

Call your doctor today:

  • New rash with fever
  • Rash after starting a new medicine
  • Hives that spread or keep coming back
Pain

Emergency care now:

  • Screaming or crying that can’t be comforted
  • Hard, swollen belly, or belly pain with green vomit or blood in the stool
  • Sudden pain or swelling in the scrotum (boys)

Call your doctor today:

  • Belly pain lasting several hours
  • Ear pain, pain when peeing, or pain with fever
  • A swollen, painful joint
Head injuries

Emergency care now:

  • Passed out, even briefly
  • Vomiting more than once
  • Seizure, confusion, or unusual behavior
  • Hard to wake, or can’t be woken
  • Clear or bloody fluid from the nose or ears
  • Babies: crying that can’t be soothed, refusing to feed, or a bulging soft spot

Is it OK to let my child sleep? Sleep after a minor bump is generally safe, and it helps healing. Keep a close eye on your child for the first several hours. If a doctor has checked your child and gives you specific instructions — including waking your child overnight — follow those instructions. If you can’t wake your child, call 911.

Poisoning, choking, and swallowed objects
  • Possible poisoning: call Poison Control at 1-800-222-1222 (free, 24/7). Call 911 if your child has trouble breathing, a seizure, or can’t be woken.
  • Swallowed button battery or magnet: go to the emergency room right away, even if your child seems fine.
  • After choking: get emergency care if coughing, wheezing, noisy breathing, or color changes continue after the episode.

Extra caution for young babies

Babies can get sick quickly and show fewer signs. Your threshold for calling should be lower the younger your baby is.

Newborns to 3 months

  • Any temperature of 100.4°F (38.0°C) or higher — call right away
  • Temperature below 97.5°F (36.4°C)
  • Missing feedings or feeding poorly
  • Fewer than 6 wet diapers in a day (after the first week)
  • Very sleepy and hard to wake for feeds
  • Yellow skin or eyes that is spreading or getting worse
  • Umbilical cord area that is red, swollen, or draining pus
  • Forceful or repeated vomiting (not just spit-up)

3 to 12 months

  • Won’t drink, or fewer wet diapers
  • Unusually sleepy, limp, or inconsolable
  • Fever with any warning sign above
  • Bulging soft spot when calm and upright
  • Breathing that looks like hard work

Toddlers and preschoolers

  • Suddenly won’t walk or put weight on a leg
  • Severe belly pain
  • Acting very confused or strange
  • Can’t be comforted despite everything you try

If your child has asthma, a heart condition, a weak immune system, or another chronic condition, follow their action plan and call earlier than you would for other children.

Trust your instincts

You know your child best. “This is different from their usual colds,” “they’re getting worse fast,” or “something is really wrong” are all good reasons to call. Doctors and nurses would rather see a child who turns out to be fine than have a family wait when something serious is happening.

911, the emergency room, or your doctor?

Call 911

  • Not breathing, or severe trouble breathing
  • Blue or gray lips or face
  • Can’t be woken
  • Seizure lasting more than 5 minutes
  • Severe allergic reaction
  • Any time your child could get worse during the drive

Drive to the ER

  • Serious but stable
  • Moderate dehydration
  • Possible broken bone or a cut that needs stitches
  • Fever in a baby younger than 3 months, if your doctor sends you in

Call your doctor first

  • Worried, but it isn’t an emergency
  • Not sure whether your child needs to be seen
  • After hours: most practices have a 24/7 nurse line that can help you decide

What to tell the doctor or nurse

  • Your child’s age and weight
  • What symptoms started, and when
  • Highest temperature, and how you took it
  • How your child is acting — playing, sleepy, or hard to wake
  • How much they’re drinking, and when they last peed
  • Medicines given, the dose, and the time
  • Allergies and ongoing health conditions

MamaBear tip: A 15-second video of your child’s breathing, taken while symptoms are happening, shows your doctor what you saw — even if your child seems better by the time you’re seen.

Common worries, answered

“I don’t want to bother the doctor.”

Calling when you’re worried is what the nurse line is for.

“The fever number tells me how sick my child is.”

How your child looks and acts matters more than the number on the thermometer.

“If I give fever medicine, I’ll hide the problem.”

It’s fine to give the correct dose for comfort. Watch how your child acts afterward — and never delay emergency care to see if medicine helps.

“I’ll search online first.”

Online information can help you prepare, but it can’t examine your child. When you’re unsure, call.

Sources

This guide is for general education and is not a substitute for medical advice, diagnosis, or treatment. Always follow your child’s doctor’s instructions. MamaBear Health is not an emergency service — if you think your child is having an emergency, call 911.

See it. Share it. Sort it.

Capture your child’s symptoms and a 15-second breathing video in MamaBear, and share it securely with your child’s care team.

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