The first year of a baby’s life is one of continuous, rapid development — and for parents, it comes with a steady stream of questions about what is normal, what warrants a call to the pediatrician, and what needs emergency attention. Most concerns that arise in infancy are manageable and temporary. A smaller number require prompt medical evaluation. Knowing the difference is one of the most useful things any new parent can have in their pocket.
This guide covers the most common health concerns pediatricians encounter in babies from birth through the first year, organized from the newborn period through later infancy.
Jaundice
Neonatal jaundice — the yellowing of a newborn’s skin and whites of the eyes — is one of the most common conditions in the first week of life, affecting approximately 60% of full-term newborns and 80% of premature babies. It is caused by elevated bilirubin, a yellow pigment produced when red blood cells break down. Newborns produce bilirubin faster than their immature livers can process and eliminate it, causing temporary buildup in the skin.
For most babies, physiological jaundice peaks around days three to five of life and resolves on its own within one to two weeks without treatment. Adequate feeding — which promotes bilirubin excretion through stool — is the most important supportive measure. When bilirubin levels become elevated enough to require intervention, phototherapy (placing the baby under special blue light) effectively breaks down bilirubin in the skin.
Jaundice that appears within the first 24 hours of life, rises very rapidly, persists beyond two weeks, or is accompanied by poor feeding, extreme lethargy, or high-pitched crying needs prompt evaluation. Untreated severe hyperbilirubinemia can in rare cases cause permanent neurological damage — a condition called kernicterus — which is entirely preventable with timely treatment.
Feeding Difficulties and Weight Gain
Feeding concerns are among the most common reasons parents contact a pediatrician in the newborn period. It is normal for newborns to lose up to 7 to 10% of their birth weight in the first few days of life — this is fluid loss, not a sign of inadequate feeding. Most babies regain birth weight by ten to fourteen days.
Signs that feeding may not be going well include a baby who is not producing at least six wet diapers per day by day four of life, weight loss exceeding 10% of birth weight, excessive sleepiness that makes waking for feeds difficult, or a mother who is in significant pain with breastfeeding. Breastfeeding challenges — poor latch, low milk supply, nipple pain — are extremely common and highly responsive to support from a lactation consultant.
Gastroesophageal reflux is a frequent cause of feeding distress in infants. Spitting up after feeds is normal and expected in the first several months — most babies spit up regularly. True gastroesophageal reflux disease (GERD) is a different situation, where reflux causes poor weight gain, refusal to feed, arching away from the bottle or breast, or signs of esophageal pain. GERD in infants typically improves significantly by six to twelve months as the lower esophageal sphincter matures.
Respiratory Concerns
When Should Breathing Patterns Concern a Parent?
Newborns breathe differently from older children and adults. Periodic breathing — short pauses of up to ten seconds followed by a cluster of rapid breaths — is normal in young infants and does not require intervention. A normal respiratory rate for a newborn is 40 to 60 breaths per minute at rest.
Signs that require immediate medical attention include breathing that consistently exceeds 60 breaths per minute at rest, visible chest retractions where the skin pulls in between or below the ribs with each breath, flaring of the nostrils, grunting with each exhale, or any bluish discoloration of the lips or fingertips. These are signs of respiratory distress and warrant emergency evaluation.
Respiratory syncytial virus (RSV) deserves specific mention. RSV is the most common cause of lower respiratory tract infection in infants and the leading cause of pediatric hospitalization in the first year of life. Most RSV infections cause mild cold-like symptoms, but in young infants — particularly those under three months, premature babies, or those with underlying heart or lung conditions — RSV can cause bronchiolitis, a lower respiratory infection that can be severe. A 2024 immunoprophylaxis agent called nirsevimab is now available in the United States to protect infants against RSV and has been recommended by the CDC’s Advisory Committee on Immunization Practices for all infants under eight months entering their first RSV season.
Fever in Infancy
Fever in a young baby is one of the most anxiety-provoking situations a new parent can face, and the appropriate response depends heavily on the baby’s age.
In infants under three months, any fever of 100.4°F (38°C) or higher is a medical emergency requiring immediate evaluation — not a wait-and-see situation. Young infants have immature immune systems and limited ability to localize infection. What appears to be a mild fever can represent serious bacterial infection including meningitis, urinary tract infection, or sepsis. Evaluation typically involves blood work, urine testing, and sometimes a spinal tap to rule out these serious causes.
In infants three to six months old, fever warrants prompt same-day pediatric evaluation. In infants over six months, fever management becomes more nuanced — the temperature level matters, but so does how the baby looks and acts. A baby who is alert, interactive, and feeding reasonably well is less concerning than one who is limp, inconsolable, or unable to be roused.
Never give aspirin to an infant or child with fever. Acetaminophen is appropriate for infants over two months and ibuprofen for infants over six months.
Colic
Colic is defined as crying in an otherwise healthy baby that lasts more than three hours per day, more than three days per week, for more than three weeks. It affects an estimated 10 to 40% of infants globally, typically beginning in the second to third week of life, peaking around six weeks, and resolving by three to four months of age.
The cause of colic is not fully understood. Current research points toward gut microbiome immaturity, gastrointestinal motility variations, and heightened sensory sensitivity as contributing factors. It is not caused by bad parenting, nor does it cause long-term developmental harm to the baby.
For parents, colic is genuinely exhausting. The most evidence-supported approaches include swaddling, white noise, gentle rhythmic motion, and skin-to-skin contact. For breastfed babies, some evidence supports a trial of maternal dairy elimination, as cow’s milk protein sensitivity can cause colic-like symptoms in a subset of infants. Simethicone drops and probiotic supplementation (specifically Lactobacillus reuteri) have been studied, with probiotics showing more consistent benefit than simethicone in several trials.
Skin Conditions
Baby skin is more sensitive, thinner, and less capable of maintaining a stable barrier than adult skin, which makes rashes and skin reactions common in the first year.
Cradle cap — seborrheic dermatitis of the scalp — presents as yellowish, crusty scales on the scalp and occasionally the eyebrows or ears. It is harmless, caused by overactive sebaceous glands rather than poor hygiene, and typically resolves on its own by six to twelve months. Gentle scalp massage with baby oil before shampooing can loosen scales.
Diaper rash is one of the most universal infant skin concerns, caused by prolonged skin contact with urine and stool, friction, and in some cases Candida yeast overgrowth. Frequent diaper changes, gentle cleansing, and barrier creams containing zinc oxide are the mainstays of treatment. Persistent or worsening rash despite barrier treatment may indicate a yeast infection requiring antifungal cream.
Eczema (atopic dermatitis) affects approximately 10 to 20% of infants and typically presents in the first six months as dry, itchy, red patches on the cheeks, scalp, and extensor surfaces of the limbs. Management focuses on consistent moisturizing with fragrance-free emollients, avoiding known triggers, and using mild topical steroids during flares under pediatric guidance.
Baby acne — small red or white pimples on the face — appears in the first few weeks of life from circulating maternal hormones and resolves without treatment by two to four months.
Is Constipation in Babies Normal?
Stool frequency varies enormously in infancy, and understanding normal ranges prevents unnecessary concern. Breastfed newborns may have several stools per day in the early weeks, then shift to as infrequently as once every seven to ten days by two to three months — this is normal because breast milk is so completely absorbed. Formula-fed babies typically stool more consistently, averaging one to three times daily.
Constipation is defined not by frequency alone but by hard, pebble-like, or pellet-shaped stools that are difficult or painful to pass. Straining that produces a soft stool is not constipation — it is the normal effort required by an infant who has not yet learned to coordinate abdominal and rectal muscles.
Persistent constipation in a young infant warrants evaluation to rule out Hirschsprung’s disease, a rare condition where a segment of the colon lacks nerve cells. The introduction of cow’s milk formula is a common trigger of constipation. Switching to a partially hydrolyzed formula sometimes helps.
Umbilical Cord Care and Infection
The umbilical cord stump typically dries, shrivels, and falls off within one to three weeks of birth. Keeping it dry — folding the diaper below it and avoiding tub baths until it has separated — is the primary care instruction. Some dried blood at the base as it separates is normal.
Signs of umbilical infection (omphalitis) requiring immediate medical attention include redness, warmth, or swelling of the skin surrounding the stump, yellow or green discharge with a foul odor, or a stump that remains soft and moist rather than drying. Omphalitis is uncommon but can spread rapidly in newborns and requires antibiotic treatment.
When to Call the Pediatrician Immediately
Beyond the specific conditions covered above, the following symptoms in any infant warrant immediate contact with a pediatrician or emergency evaluation:
Any fever in a baby under three months old. Extreme lethargy or difficulty waking. Persistent vomiting, especially if projectile. Significant decrease in wet diapers or signs of dehydration including sunken fontanelle, no tears when crying, or dry mouth. Any respiratory distress. A seizure. A rash that appears as small, non-blanching red or purple spots — which may indicate meningococcal infection. Inconsolable crying that is different in character from the baby’s normal cry.
For Boston-area parents, Boston Children’s Hospital — ranked the number one children’s hospital in the United States — operates a 24-hour pediatric urgent care and emergency department. For evidence-based guidance on infant health topics between appointments, the American Academy of Pediatrics’ parent resource site HealthyChildren.org is the most authoritative and comprehensive reference available.
Frequently Asked Questions
How many wet diapers should a newborn have per day?
By day four of life, a newborn should produce at least six wet diapers per day. Fewer than this is a signal that the baby is not getting adequate fluid intake and warrants a call to the pediatrician.
When do babies start sleeping through the night?
Most babies are not developmentally ready to sleep through the night consistently until around four to six months of age. Expecting a newborn to sleep through the night is unrealistic and can lead to unnecessary frustration.
Is it normal for a baby’s breathing to sound noisy?
Mild noisy breathing from mucus in the nasal passages is common and usually harmless. A high-pitched squeaky sound with each breath — called stridor — or a persistent wet rattling sound warrants evaluation to rule out anatomical or respiratory causes.
