Call your pediatrician right away if your newborn has a fever of 100.4°F (38°C) or higher, is breathing with difficulty, is very hard to wake, won't feed, or has fewer wet diapers than usual. For a newborn under 3 months, a fever is always treated as urgent. When in doubt, it is always right to call — trusting your instincts is part of good newborn care.
This guide explains the warning signs that need urgent attention, the ones that mean "call the doctor today," and the noisy-but-normal things newborns do that often worry parents unnecessarily. It is a guide to when to seek help, not a tool to diagnose your baby.
Emergency signs: get help immediately
Call emergency services (911 or your local number) or go to the nearest emergency department if your newborn shows any of these:
- Difficulty breathing: gasping, grunting with each breath, the skin pulling in around the ribs or neck, or long pauses in breathing (more than about 10 seconds).
- Turning blue: a blue or grey colour on the lips, tongue, or face.
- Unresponsive or limp: very difficult to wake, floppy, or not responding to you.
- A seizure: jerking, stiffening, or staring episodes.
- Severe, inconsolable crying that is unusual for your baby, or a weak, high-pitched cry.
- A rash of tiny purple-red or bruise-like spots that don't fade when you press a glass against them — this can signal a serious infection (like meningitis or sepsis); get emergency help now.
These are medical emergencies. Do not wait to see if they pass.
Call your pediatrician the same day
Contact your pediatrician promptly — the same day — for signs like these:
- Fever of 100.4°F (38°C) or higher in a baby under 3 months — this always needs urgent medical assessment.
- Low temperature (below about 97°F / 36.1°C) that doesn't come up with an added layer.
- Signs of dehydration: far fewer wet diapers, a dry mouth, no tears, or a sunken soft spot on the head.
- Repeated or forceful vomiting, or vomit that is green or contains blood.
- Poor feeding: refusing feeds, feeding much less than usual, or being too sleepy to feed.
- Worsening yellow colour of the skin or eyes (see the jaundice section below).
- A new rash, especially with a fever (see the emergency note above about spots that don't fade when pressed).
If you can't reach your pediatrician and you're worried, seek urgent care — it is always better to be checked.
Fever in a newborn
Fever is measured differently at this age because a newborn's immune system is still developing. Key points:
- The threshold is 100.4°F (38°C), measured rectally, which is the most accurate method for young babies.
- Under 3 months, any fever is urgent — it needs same-day medical assessment, even if your baby seems otherwise well. Do not give fever medicine to a young baby unless your doctor tells you to.
- A low temperature can also signal illness in newborns, so a baby who feels unusually cold and won't warm up should be checked too.
Because early infections in newborns can develop quickly, doctors deliberately take fever in this age group very seriously — so should you.
Newborn jaundice: when to worry
Jaundice — a yellow tint to the skin and the whites of the eyes — is very common in the first days of life and is usually mild and harmless. It happens because a newborn's liver is still learning to clear a substance called bilirubin.
- Usually normal: mild yellowing that appears after day 2–3 and fades over the following week, in a baby who is feeding and behaving normally.
- Call the doctor if: the yellow appears in the first 24 hours, spreads to the belly, arms, or legs, deepens instead of fading, or comes with poor feeding, sleepiness, or pale poop and dark urine.
- Feeding helps: frequent feeding helps your baby clear bilirubin. Mild jaundice is often monitored, while higher levels may need treatment such as phototherapy.
Your pediatrician can measure bilirubin levels and advise whether treatment is needed. When jaundice is deepening or you're unsure, always have it checked.
Breathing: what's normal and what's not
Newborn breathing is naturally irregular, which surprises many parents. It's normal for a newborn to breathe fast for a bit and then slow down, and to have brief pauses of a few seconds. What is not normal, and needs urgent help:
- Pauses in breathing longer than about 10 seconds, or pauses with colour change.
- Constant fast breathing, flaring nostrils, grunting, or the chest pulling in with each breath.
- A blue tint to the lips or face.
If breathing looks like hard work rather than a passing irregular rhythm, treat it as an emergency.
Feeding and diapers as health signals
How your newborn feeds and how many diapers they produce are among the clearest signs of health in the early weeks:
- Feeding: regular feeds every 2–3 hours with periods of contentment afterward is reassuring. Refusing feeds or feeding much less than usual is a reason to call.
- Wet diapers: a rough guide is about 6 or more wet diapers a day after the first week. A sharp drop can signal dehydration.
- Poop colour: after the first days, poop is usually yellow, green, or brown. Pale, chalky-white poop or dark urine should always be checked, as they can relate to jaundice or the liver.
Noisy but normal: things that often worry new parents
Many alarming-seeming newborn behaviours are completely normal. These usually do not need a doctor on their own:
- Sneezing, hiccups, and grunting — common ways a newborn clears their nose and settles their digestion.
- Irregular breathing during sleep, with brief pauses and bursts, in a baby who is otherwise pink and comfortable.
- Spit-up after feeds, in small, easy amounts.
- Occasional trembling of the chin or hands, and startling at noises.
- Mild, brief yellowing after day 2–3 that fades, in a well baby.
Knowing what's normal helps you save your worry — and your pediatrician's time — for the signs that truly matter. But this list never overrides your instincts: if something feels wrong, call.
Keep reading
For everyday care, see our complete guide to newborn care, our complete guide to feeding your newborn, and our complete guide to newborn sleep.
Frequently asked questions
When should I call the doctor for my newborn?
Call right away for a fever of 100.4°F (38°C) or higher in a baby under 3 months, difficulty breathing, blue colour, a baby who is very hard to wake or won't feed, repeated or green vomiting, or signs of dehydration. When in doubt, always call — it's better to be checked.
What temperature is a fever in a newborn?
A fever is a rectal temperature of 100.4°F (38°C) or higher. In a baby under 3 months, any fever needs urgent, same-day medical assessment, even if your baby otherwise seems well.
Is newborn jaundice dangerous?
Mild jaundice appearing after day 2–3 is common and usually harmless, especially with frequent feeding. Call your doctor if the yellow appears in the first 24 hours, deepens or spreads, or comes with poor feeding, sleepiness, or pale poop — higher bilirubin levels sometimes need treatment.
Is it normal for a newborn's breathing to be irregular?
Yes — newborns often breathe fast then slow, with brief pauses of a few seconds. This is normal in a comfortable, pink baby. Pauses longer than about 10 seconds, constant fast or laboured breathing, grunting, or a blue tint need emergency care.
What newborn symptoms are usually not an emergency?
Sneezing, hiccups, grunting, small spit-ups, brief chin trembling, and mild yellowing after day 2–3 in an otherwise well baby are usually normal. Still, if any symptom worries you or your baby seems unwell overall, trust your instincts and call.
Medical disclaimer: This article is for general information only and is not a substitute for professional medical advice, diagnosis, or emergency care. It cannot tell you what is wrong with your baby. If you think your newborn may be seriously unwell, call your pediatrician or emergency services immediately — do not delay. Always follow the guidance of qualified healthcare professionals. See our full medical disclaimer.
Reviewed by the Babbez Editorial Team. Sources: American Academy of Pediatrics (AAP), Mayo Clinic, NHS.