Before becoming a parent, most people have a working knowledge of when they are unwell — they feel it, they can describe it, they can decide whether to see a doctor. Caring for a baby removes all of that. A baby cannot tell you where it hurts, cannot describe a symptom, and cannot participate in the assessment of how serious something is. That responsibility falls entirely on you — which is why new parents describe health anxiety in the first year as one of the most consistent and demanding aspects of early parenting. This guide gives you a practical foundation: what to watch for, what the common conditions actually are, and how to make confident decisions about when to seek help.

Learning to Read Your Baby’s Signals

Before any specific conditions or symptoms, the most important skill in baby health is learning what your individual baby’s baseline looks and feels like. A baby who is well fed, adequately rested, and in good health has a characteristic quality of alertness, responsiveness, and engagement that experienced parents learn to recognise without conscious analysis.

When something is wrong, the change from baseline is usually the first and most reliable signal — before any specific symptom you could name. A baby who is quieter than usual, feeding less enthusiastically, less responsive to your face and voice, or sleeping differently from their norm is telling you something. Trust that signal and investigate rather than waiting for a recognisable symptom to appear.

Fever in Babies: A Calm, Practical Guide

Fever is one of the most common reasons parents call their GP or health visitor in the first year — and one of the most anxiety-inducing, partly because the guidance differs significantly by age.

Temperature thresholds that matter

• Under 3 months, temperature of 38°C or above: Same-day medical assessment is recommended regardless of how well the baby appears. Very young babies have immature immune systems and can deteriorate rapidly.
• 3–6 months, temperature of 39°C or above: Same-day medical assessment recommended.
• Over 6 months: Fever threshold becomes less important than the baby’s overall presentation — how they are feeding, their responsiveness, and whether they can be comforted.

Managing fever at home

For a baby over 3 months who is otherwise well — feeding, alert, consolable — infant paracetamol in the correct dose for age and weight can help with comfort. Do not alternate paracetamol and ibuprofen unless directed by a health professional. Keep the baby comfortably dressed — not over-bundled — and ensure fluid intake is maintained. A fever that is not responding to paracetamol, or a baby who seems increasingly unwell despite treatment, warrants prompt medical review.

The Red Flag Symptoms: Always Act Immediately

These symptoms require emergency medical attention — call 999 or go directly to your nearest emergency department:

• Difficulty breathing: rapid breathing, nostril flaring, visible rib or neck muscle movement with each breath, blue lips or skin
• A rash that does not fade when a clear glass is pressed firmly against it (this is the glass test for a meningococcal rash)
• A high-pitched cry that is unusual and different from the baby’s normal cry
• A baby who is unusually drowsy and cannot be roused, or who is unresponsive
• A bulging fontanelle (the soft spot on top of the head) — especially with fever or other symptoms
• A seizure (fit) — any convulsive movement that the baby cannot be brought out of

If you are ever unsure whether a symptom is urgent, call NHS 111 (UK) for immediate guidance. The cost of an unnecessary call is nothing. The cost of a delayed call can be significant.

Common Baby Health Conditions in the First Year

Colic

Colic is defined as episodes of intense, inconsolable crying in an otherwise healthy baby, typically in the late afternoon or evening, in a pattern that persists for more than three weeks. It affects approximately 1 in 5 babies, usually beginning around 2–3 weeks and typically resolving by 3–4 months. Its cause is not fully understood, and there is no reliably effective treatment — though certain approaches (gentle movement, white noise, different feeding positions for wind) may help some babies. The impact on parents is significant; taking turns with a support person, and putting the baby in a safe place and stepping away briefly when overwhelmed, is a completely appropriate response.

Eczema

Eczema (atopic dermatitis) is common in babies, typically presenting as dry, red, itchy patches on the face, scalp, and in skin creases. Regular, generous application of an unperfumed emollient (moisturiser) is the foundation of management. Avoid soap and bubble bath — use an emollient as a wash instead. If eczema is widespread, weeping, infected (crusting, increasing redness, warmth), or not responding to moisturiser, a GP appointment is appropriate. Eczema is manageable and often improves significantly as children grow.

Reflux

Posseting — bringing up small amounts of milk after feeds — is normal in babies and does not require treatment if the baby is otherwise well, growing, and not in distress. More significant reflux (frequent large vomiting, visible discomfort during and after feeds, arching of the back, refusal to feed) may indicate gastro-oesophageal reflux disease (GORD) and is worth discussing with a GP, who can advise on feeding adjustments and, if necessary, medication.

Jaundice

Newborn jaundice — yellowing of the skin and whites of the eyes caused by elevated bilirubin — is common in the first week and usually resolves without treatment. Jaundice that appears in the first 24 hours, that is severe, or that persists beyond two weeks warrants medical assessment. Your midwife and health visitor will check for jaundice at routine visits in the early weeks.

“”Parents know their baby better than anyone in a clinical setting ever will. The most powerful tool in baby health is a parent who has learned to trust their own observations — and who knows how to act on them.””

— Dr. Ranj Singh, NHS paediatric emergency medicine doctor, broadcaster, and author of How to Grow a Baby Journal. Dr. Ranj has spent his career both treating babies and communicating clearly with the parents who care for them. His consistent emphasis on parental observation as a clinical tool — not an unreliable anecdote — is the perspective that most directly empowers the approach in this guide.

For specific guides on individual baby health topics — including managing eczema, understanding vaccinations, and recognising signs of infection — explore our full Baby Health guide collection in the Health and Safety section.

Frequently Asked Questions

How do I take my baby’s temperature accurately?

A digital thermometer placed in the armpit (axillary) is the recommended method for babies under five years. Ear thermometers can be used from six months but are less reliable in young babies due to small ear canal size. Forehead strip thermometers are not accurate enough for medical decisions. If your reading concerns you, repeat it after a few minutes and check alongside your baby’s overall presentation.

When do babies have their vaccinations?

In the UK, the routine childhood vaccination schedule begins at 8 weeks, with further sets at 12 weeks, 16 weeks, and one year. Each set protects against multiple serious diseases. Common post-vaccine reactions — mild fever, fussiness, a sore leg — are normal and typically resolve within 48 hours. If you have questions about any vaccine, your health visitor or GP can discuss the evidence with you.

My baby has a cold — what can I do?

Most colds in babies resolve within 7–10 days without medical treatment. Saline nasal drops can help with congestion, and ensuring the baby is feeding and hydrated is the priority. See a GP if: the baby is under three months old, breathing becomes laboured or rapid, fever develops or persists, or the baby is significantly unwell beyond typical cold symptoms. Cough and cold medicines are not recommended for children under six.

Should I be worried about flat spots on my baby’s head?

Positional plagiocephaly — flat spots on the back or side of the head caused by pressure in one position — is common and usually cosmetic. It typically improves with repositioning (supervised tummy time, varying which side the baby faces when lying down) and resolves as the baby becomes more mobile. Speak with your health visitor if you notice a significant flat spot; they can assess whether it requires any further attention.

Key Takeaways

• Learning your baby’s individual baseline of alertness and responsiveness is the most important baby health skill — change from baseline is your earliest warning signal.
• Fever in babies under three months (38°C+) always warrants same-day medical assessment, regardless of how well the baby appears.
• Red flag symptoms — difficulty breathing, non-blanching rash, unresponsiveness, unusual high-pitched cry — require emergency medical attention immediately.
• Colic, eczema, posseting, and newborn jaundice are common conditions that are manageable and usually resolve with time or simple treatment.
• If you are ever unsure, calling NHS 111 or your health visitor is always the right move — no call is ever a wasted call when your baby’s health is the question.

Health confidence as a new parent does not come from knowing every medical fact — it comes from knowing your baby well enough to recognise when something has changed, and knowing clearly what to do when it does. That combination — attentive observation and clear action thresholds — is what this guide is designed to build. You will not get every call right, and neither does anyone else. What matters is that you keep making them.