When to Call the Doctor: Newborn Symptoms You Should Never Ignore

Knowing which newborn symptoms warrant an urgent call to the doctor is one of the most important pieces of knowledge new parents can have — and one of the least confidently held. The early weeks with a newborn are full of small worries and normal variations that don’t require action, but they also carry the possibility of genuine emergencies that can deteriorate quickly in very young babies. This article provides a clear, evidence-based guide to the symptoms that should prompt immediate action: when to call NHS 111, when to go straight to A&E, and when to call 999. We draw on NHS and NICE clinical guidance throughout. Bookmark this page — knowing it is there is itself a form of reassurance.

High Fever in Newborns: The 38°C Rule

A fever in a newborn — defined as a temperature of 38°C (100.4°F) or above — is a medical emergency in babies under three months of age. This is one of the clearest, most consistently stated rules in NHS and NICE guidance.

In newborns and young infants, the immune system cannot yet localise infection effectively. A fever that might indicate a mild upper respiratory infection in a toddler could indicate bacterial meningitis, sepsis, or a serious urinary tract infection in a baby under three months. These conditions can deteriorate from apparently unwell to critically ill within hours.

What to do: If your baby is under three months and has a temperature of 38°C or above, do not wait and see. Call NHS 111 immediately, or take them to A&E. Do not give paracetamol to lower the fever in a baby under two months (the licensed age for infant paracetamol), and do not give ibuprofen to any baby under three months.

Temperature should be measured rectally or axillary (under the arm) using a digital thermometer. Forehead strip thermometers are not reliable for clinical decision-making. Ear thermometers require correct positioning to be accurate in babies under six months.

Breathing Difficulties

Newborns breathe irregularly — they may have short pauses (periodic breathing) of up to ten seconds, which is normal. However, the following signs indicate a potential breathing emergency:

• Grunting with each breath: Expiratory grunting is a sign the baby is working hard to keep air in their lungs and can indicate respiratory distress syndrome, pneumonia, or sepsis.
• Nostril flaring: The nostrils flaring widely with each breath indicates increased respiratory effort.
• Chest recessions: When you can see the muscles between the ribs, above the sternum, or below the ribcage pulling inward with each breath, the baby is working significantly harder than normal to breathe.
• Breathing rate: Normal newborn respiratory rate is 30–60 breaths per minute. Consistently above 60 is tachypnoea (fast breathing) and warrants assessment. Below 30 with colour changes is also a concern.
• Apnoea: A pause in breathing lasting more than 15–20 seconds, or any pause accompanied by colour change (blue, pale, mottled), is an emergency. Call 999.

Jaundice: When Yellow Means Urgent

Jaundice — a yellow colouring of the skin and whites of the eyes caused by elevated bilirubin — affects up to 60% of term newborns in the first week of life and is usually harmless. However, certain patterns of jaundice require urgent assessment:

• Jaundice appearing in the first 24 hours: Early-onset jaundice can indicate haemolytic disease of the newborn (blood group incompatibility) and requires same-day investigation. Call your midwife immediately.
• Jaundice spreading to the abdomen, arms, and legs: This indicates higher bilirubin levels. Yellow colouring confined to the face and chest is less urgent than jaundice spreading down the body.
• A sleepy, floppy, difficult-to-rouse baby with jaundice: High bilirubin is toxic to brain tissue (kernicterus). A jaundiced baby who won’t wake for feeds or is unusually floppy needs same-day emergency assessment.
• Jaundice persisting beyond two weeks in a formula-fed baby (three weeks in a breastfed baby) is prolonged jaundice and needs investigation, as it can indicate liver conditions including biliary atresia — a surgically treatable but time-critical condition.

Feeding Refusal and Dehydration Signs

A baby who suddenly and completely refuses to feed, or whose feeding has dramatically dropped off, needs assessment — particularly if it is associated with other symptoms.

Signs of dehydration to look for include:

• Fewer than six wet nappies in 24 hours after day five
• Dark yellow, strong-smelling urine (or “brick dust” — orange crystals — in nappies in older babies)
• Sunken fontanelle (the soft spot on top of the head appears sunken inward)
• Dry mouth and mucous membranes
• Sunken eyes
• Very poor skin turgor (skin tent when gently pinched)
• Extreme lethargy or unresponsiveness

If your baby shows these signs, contact NHS 111 or go to A&E. Do not attempt to rehydrate with water — continue breast or formula feeding and seek medical advice immediately.

Fontanelle Changes

The fontanelle — the soft spot on the top of a newborn’s head — provides a window into intracranial pressure. Two changes require urgent attention:

• Bulging fontanelle: A fontanelle that is visibly tense or bulging when the baby is calm and upright can indicate raised intracranial pressure. This is a red flag for meningitis, encephalitis, or hydrocephalus. Seek emergency care immediately.
• Very sunken fontanelle: Combined with other dehydration signs, a very sunken fontanelle indicates significant fluid deficit requiring urgent medical treatment.

Note: the fontanelle normally pulses slightly with heartbeat and may appear slightly full when a baby is crying or lying flat — this is normal.

Skin Colour Changes: Blue, Pale, and Mottled

Changes in skin colour are among the clearest signs of a circulatory or respiratory emergency in newborns:

• Central cyanosis (blue lips and tongue): A blue tinge to the central mucous membranes (lips and tongue, not just the hands and feet) indicates inadequate oxygenation. Call 999.
• Pallor: Unusual paleness, particularly if combined with limpness or poor responsiveness, can indicate shock, sepsis, or severe anaemia.
• Mottling: A lacy, marbled pattern on the skin that doesn’t improve with warming can indicate poor circulation and sepsis.
• Non-blanching rash: Press a glass against a rash — if the spots do not fade, call 999 immediately. This can indicate meningococcal disease.

Frequently Asked Questions

When should I call 999 for my newborn?

Call 999 immediately if your newborn: stops breathing, turns blue around the lips or tongue, is unresponsive or unconscious, has a seizure, or has a non-blanching rash. These are emergencies that cannot wait.

When should I use NHS 111 for a newborn concern?

NHS 111 is appropriate for urgent but not immediately life-threatening concerns: fever in a baby under three months, jaundice you’re unsure about, feeding refusal, or symptoms you can’t assess yourself. NHS 111 can also dispatch a clinician or arrange an emergency appointment.

How do I take my newborn’s temperature accurately?

A digital thermometer used under the arm (axillary) is the most practical method for home use. Hold the arm gently against the thermometer for the specified time. Rectal temperature is most accurate but is typically performed in clinical settings. Add 0.5°C to an axillary reading if comparing to a rectal reference range.

Is it normal for a newborn to have blue hands and feet?

Yes. Acrocyanosis — blue or purple colouring of the hands and feet — is normal in newborns, especially in the first few days of life and when they are cold. It is the central cyanosis (blue lips and tongue) that signals a problem.

Conclusion

Most newborn symptoms are benign variations of normal — but the few that are not can deteriorate fast. The key decision rule to remember: fever above 38°C in under three months = emergency, every time. Save NHS 111 (call 111 or use 111.nhs.uk) in your phone contacts now, before you need it. If you are ever in doubt about whether a symptom is serious, call — clinical teams would always rather hear from a worried parent and reassure them than have a family wait too long on a genuine emergency.