Guide to Baby Health in the First Year From A to Z

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From colds and colic to rashes and vaccines, consider this your just-in-case guide.

By Jessica D'Argenio Waller, MS, CNS, LDN July 29, 2023

Lea Csontos/Stocksy

My kids’ pediatrician once described bringing a newborn home from the hospital akin to “bringing home an alien,” and well, she was right. This strange new creature knows nothing of this new world they’ve entered, they’re up at all hours, and seem to change practically overnight. It’s why life with a newborn is equal parts awe-inducing and baffling.

In between trying to track their feeding and sleeping schedules, growth and milestones, questions pop up around everything from baby acne to eczema, vitamins to vaccines, leaving you wondering exactly what is normal with your new normal. Consider this list—an A to Z guide to baby health in the first year—a primer for what you need to know. I hope it helps make life with your own tiny alien a little calmer.

Editor’s note: The information included in this article is for reference only and is not intended as medical advice. If you have questions or concerns about your baby’s health, reach out to your pediatrician.

If you thought only pubescent teenagers got acne, think again. Baby acne is a normal occurrence in the first two months of life (so cruel!), and consists of tiny pimples that arise due to stimulation of the oil glands in the skin by hormones passed via the placenta during pregnancy.

The American Academy of Pediatrics (AAP) recommends gently washing baby’s face once a day with mild baby soap to remove any milk residue, and opting for gentle detergents when laundering sheets and burp cloths. Harsh detergents can irritate their sensitive skin further.

Related: Answers to questions about baby skin woes—straight from a pediatric dermatologist

Wondering if your baby has a food allergy? If you’re breastfeeding, small traces of the food you eat make their way into your breast milk, and some foods can cause a reaction in your baby.

That can seem worrying, but know that most babies don’t have a reaction to their mother’s breast milk. Experts generally recommended that breastfeeding mothers should follow their current diet, and change it only if they notice signs of a food allergy or intolerance in their baby.

It’s also possible that a baby could develop an allergy to an element of formula or to a solid food they’ve tried (after the age of 6 months).

According to AAP, here’s what to look for:

True allergic reactions are typically more severe in how they present than an intolerance. You might notice symptoms such as vomiting, wheezing, hives and blood in stool for a true allergy. For an intolerance, symptoms are much more gradual and understated, including irritability, eczema, reflux and stool issues.

Related: The 8 most common allergies mamas should have on their radar

If you think your breastfed baby might have a food allergy or intolerance, bring it up with your baby’s pediatrician, who may recommend eliminating the food from your diet for 2 to 3 weeks to see if your baby’s symptoms improve. Note that symptoms may not improve immediately—it can take a week or longer for your little one to start to feel better, as some allergens, like cow’s milk proteins, can still circulate for up to 3 weeks after elimination.

If you suspect an allergy or intolerance in your formula-fed baby, talk to your child’s pediatrician about changing to a hypoallergenic formula that uses a hydrolyzed casein-based protein, which may be better tolerated. Goat’s milk or soy protein formulas are also available, and may be worth trying, though some infants with cow’s milk protein allergy will also react to soy or goat’s milk. Your pediatrician should be able to help figure out the best path forward.

Babies wiggle—especially as they work on tummy time and rolling over. Avoid leaving your little one unattended on any type of elevated surface, like a changing table, bed or couch, which could result in an accidental fall or bump. Once your baby becomes more mobile, bruises and bumps are bound to happen as they get bolder in exploring their environment. These small injuries occur no matter how well you babyproofed—they’re nearly impossible to avoid, says AAP. “Just be matter-of-fact about these mishaps. Offer a quick hug or a reassuring word and send her on her way again. She won’t be unduly upset by these falls if you’re not,” the organization writes.

Keeping a baby-friendly ice pack and some arnica gel on hand can help reduce the pain and bruising level. If you’re worried about a possible head injury, reach out to your child’s pediatrician to run through the symptoms you might be seeing.

Related: 20 babyproofing products to protect your little one in every room of the house

From sunburns to scalds, a baby’s sensitive skin can be highly susceptible to burns. Check your home’s hot water heater temperature—lowering to 120 degrees Fahrenheit is the safest bet. Around 100 degrees Fahrenheit is recommended for a comfortable bath, which will feel warm (not hot) on your wrist. And remember to keep hot liquids, like your morning coffee, out of their tiny arm’s reach.

For outings, because babies under 6 months shouldn’t wear sunscreen—they’re at a greater risk of developing a rash as a side effect, keep them covered but cool in sun hats and lightweight clothing. Once baby is beyond 6 months of age, they can start wearing baby-safe sunscreen. Avoid hard-to-control aerosol sunscreen sprays in favor of a standard cream-based sunscreen.

Many dermatologists recommend physical or mineral-based formulas for young children, with an SPF of at least 30. (Psst: make application more fun for your mini by using a beauty blender sponge.)

Of course, being smart about sun exposure can go a long way. Because their delicate skin is so sensitive, keeping them out of the sun for the most part is best practice.

Related: 10 best sun hats for babies and toddlers (that they’ll actually keep on their heads)

Because newborn babies have still-developing digestive systems and teeny stomachs, even a small amount of air bubbles can bring major discomfort. Burping after each feeding—or sometimes in between—can help release gas and pressure and make them more comfortable.

Related: Mom relieves baby’s gas like a pro in viral TikTok

In any of these positions, you’ll want to ensure that your baby’s back is straight and flat, not curved. Using a cupped hand, offer repeated gentle pats on their back to help release gas. (Have a burp cloth handy in case spit up makes an appearance.) By 3 months, your baby may not need burping after every feeding, but if they seem fussy after eating, try a burp or a position change.

Your baby’s first cold is a milestone no parent is rushing to reach. It’s always hard when your little one is sick, but most kids will have 8 to 10 colds before they turn 2 years old, AAP notes. And most come and go without any problems.

Related: 12 must-have products for baby during cold & flu season

Just keep an eye on their temperature and make sure to keep them hydrated and well rested. Babies’ immune systems are still developing, so it’s important to watch for signs of high fever or viruses that can impact breathing, like RSV. If you have any concerns, it’s always encouraged to reach out to your child’s pediatrician.

AAP recommends keeping your child home if they are experiencing the following:

As always, reach out to your child’s pediatrician for guidance if your baby is experiencing any of the above symptoms.

Colic is a term for when an otherwise healthy baby cries a lot for no clearly understood reason. The catch-all condition is diagnosed by the 3/3/3 rule: When an infant under 3 months of age cries for more than three hours, more than three days a week. But it can be serious: Colic may contribute to feeding issues in babies.

Doctors don’t truly know what causes colic: It could be related to a sensitivity to some component of breast milk or formula, but they do know it’s not caused by gassiness. Some colicky babies also have gas due to the amount of air they swallow when crying—but it’s not gas that’s causing the colic.

Related: How to help a colicky baby

Colic could also be related to overstimulation, a baby’s inability to calm themselves or sensitivity to the sights and sounds of their environment. The good news? Colic typically goes away by the time a baby is 3 or 4 months old. In the meantime, going for walks, babywearing, infant massage and other soothing activities can be helpful in caring for a colicky baby.

Talk to your baby’s pediatrician if you feel like your little one is crying nonstop or seems inconsolable, especially later in the day or evening hours. They might recommend a gentle elimination diet if you’re breastfeeding, a formula change, or probiotic drops.

Related: Probiotics may be the answer to soothing your baby’s colic

If your baby has a congested nose, it can make feeding and eating more difficult, so you may need to increase the frequency of feeds (just offer smaller amounts at each one). It may also affect sleep. Saline nasal sprays can help loosen mucus in stuffy nasal passages, and running humidifiers can make it easier for tiny noses to breathe. Ask your pediatrician about using a baby-safe chest rub for congestion once your infant is over 2 months old.

Many babies tend to look like they’re straining when having a bowel movement, and a cry or going red in the face while pooping is all within the realm of normal (it’s hard to poop laying down!). But if your newborn is passing hard, dry stools, they could be constipated.

According to AAP, signs of infant constipation may include:

Related: 5 toddler constipation tips for when they can’t ‘go’

If your infant is over 1 month old, you can try offering them a little apple juice or pear juice. Juice isn’t typically recommended for babies under 1 year, but the sugars in these fruit juices help draw liquid into the intestines and can be helpful for constipation, AAP notes.

Try offering 1 ounce a day for every month of life up to about 4 months (a 1-month-old baby would get 1 ounce; a 5-month-old baby would get 4 ounces) until symptoms resolve. If juice doesn’t seem to do the trick, your pediatrician can help navigate next steps.

A cough can be concerning in your little one, given their tiny airways, but rest assured that coughing is a natural reflex to help their body get rid of harmful germs. Of course, coughs can range from mild to more serious, from a dry or wet cough to the wheezing or barking common with croup or whooping cough (pertussis).

While cold medicines and cough suppressants shouldn’t be used in kids under 4, in some cases, the cough may be a symptom of a bacterial infection requiring antibiotics, so it’s good to call your pediatrician if your baby’s cough is worrying you. Signs of increased concern would be if the cough appears with a high fever or vomiting or your baby is showing signs of respiratory distress (in the latter case, head to the emergency room).

Around 3 to 4 weeks after birth, your baby’s beautiful head might show signs of redness or scaly, flaky skin. Cradle cap, or seborrheic dermatitis, is a highly common, non-contagious skin condition that may be a result of an overproduction of oil related to hormonal changes. Doctors aren’t really sure why it happens, and it’s unlikely to be uncomfortable or itchy for your infant. Rest assured that it’s not related to an allergy or hygiene issue. Cradle cap tends to go away on its own in a few weeks to months, but it can be tough to just watch and wait.

Cradle cap can be managed at home if it’s confined to your baby’s scalp, AAP says. In some cases, seborrheic dermatitis can also be found on the face and groin, too. If this is the case, reach out to your pediatrician for tips.

The red, angry rash that forms in your baby’s diaper area is known officially as diaper dermatitis, and is often a fact of life in these early stages, thanks to all those wet diapers. A diaper rash cream used after diaper changes can help, as can airing out your baby’s bum by going diaper-free for short periods. One small study found that even applying breast milk to baby’s bum can be as effective as topical hydrocortisone 1% cream for relieving diaper rash. If over-the-counter diaper rash creams aren’t seeming to help, reach out to your child’s pediatrician.

Related: 14 diaper rash creams that *really* work

Is your 5-month-old baby distracted while breastfeeding or bottle feeding? Distracted feeding becomes especially common between months 3 and 5, as their vision improves and they want to play more and engage with their environment. It’s normal and developmentally appropriate, notes La Leche League, but that doesn’t mean it’s not frustrating at times. If it’s taking your little one longer to finish a feeding session than it used to, or if you’re worried they’re not getting enough milk, we’ve got some tips to help baby stay focused on feeding.

Drooling might start around 3 months, but it doesn’t necessarily mean that their first teeth are right around the corner. Drooling becomes much more heightened between 4 and 6 months (enter: cute bibs!). But know that saliva serves a few big biological functions for your baby, including supporting digestion, keeping (future) teeth clean and making it easier to swallow.

Note, however, that if your little one is suddenly drooling but also can’t make sounds and is having trouble breathing, they could be choking—call 911 immediately.

Redness, rashes, flaking and small bumps can be par for the course when it comes to newborn skin, as hormone levels balance out and they get used to their new environment (outside the womb, that is). Stay away from strong lotions or creams, but gentle calendula oil or jojoba oil can be safe and soothing, as can a bit of breast milk rubbed in (just more proof breast milk is basically magic). Talk to your baby’s doctor if that rash or dryness isn’t going away or is spreading, as it could be a sign of eczema (more below) or another skin condition.

Is it dry skin or eczema? Upwards of 25% of babies have eczema, according to the American Academy of Dermatology Association, which can develop as a result of babies’ more sensitive skin barrier. While dry skin is relatively harmless and painless, eczema is known as the itch that rashes, and it can be super itchy, red and weepy, and generally much more uncomfortable for babies. It often appears on the face, elbows and knees.

Related: How to treat your child’s eczema

Note: If your child is under 2 months and spikes a fever at or above 100.4ºF, head to the emergency room for immediate medical treatment. If your child is older than 60 days, call your pediatrician for guidance. If the fever is under 102ºF, they may recommend monitoring at home or coming in for a visit, and may also recommend Tylenol (acetaminophen)—but they’ll have to give you correct dosing information based on your child’s age and weight. If your child of 3 months has a fever of 102ºF or above, or if your child of any age has a fever of 104ºF or higher, seek immediate medical treatment.

Generally speaking, fevers are a sign that your baby’s immune system is functioning well, and in many cases, the best course of action is to keep your baby hydrated and let the fever run its course. But if you’re worried about your baby’s fever, be sure to take note of all their symptoms, including how long the fever has lasted. If your little one has had a fever for more than 24 hours, has a sore throat, runny nose, stiff neck, what seems like a severe headache, is having a tough time sleeping or seems unusually drowsy or lethargic, be sure to reach out to your pediatrician. They can assess whether more action is needed.

Babies under 6 months should not take ibuprofen (Motrin). And remember, children and teens under the age of 18 years should not be given aspirin due to the risk of a dangerous illness called Reye syndrome.

It’s also important to be aware that in some cases, a fever can cause a febrile seizure in babies and young children. Most common in babies between 6 months and 5 years of age, febrile seizures can be shocking to observe but are generally harmless and require minimal treatment.

“A febrile seizure by definition is a seizure which occurs after a fever. If a seizure occurs in the absence of a fever, then it’s not a febrile seizure, it’s something else,” explains Ashlesha Kaushik, MD, FAAP, an American Academy of Pediatrics (AAP) national spokesperson, pediatric infectious disease specialist and clinical assistant professor of pediatrics at the University of Iowa.

“It’s the speed with which the fever rises that’s the key—not the height of fever, but the sudden rise of fever that can give them a [febrile] seizure,” Dr. Kaushik adds.

According to the Centers for Disease Control and Prevention (CDC), most febrile seizures last for less than one or two minutes. If your child experiences a febrile seizure, the best thing to do is to call your pediatrician for advice and possible assessment.

Related: New guidelines for infants with fevers: Here’s what parents need to know

All food is new food to an infant, whether that’s breast milk or formula, and gas is a normal part of their digestive process. It can cause some discomfort, however, so taking steps to reduce gas in infants can be helpful in preventing future fussiness.

There’s no real evidence that certain foods cause more gas in babies than others, which means that yes, you can keep eating broccoli. If your baby has a true sensitivity to certain food groups, such as dairy, you may notice other symptoms, such as more spitting up, excessive fussiness, rash, diarrhea or other changes. In those cases, your physician may recommend you eliminate dairy (dairy, eggs and peanuts are the most common causes of food allergies in babies) for two weeks to see if symptoms improve.

Ask your pediatrician about baby probiotics, too, which may help with digestive discomfort.

Yep, your baby’s poop can hold clues to their health. The key factor is figuring out what’s considered “normal” for your infant, as all babies are different, and poop output may depend on how they’re fed. It’s then the big variations that may signal that something is off, like if your baby dirties 4 diapers a day and then suddenly doesn’t poop for a whole day that may warrant a check-in with the pediatrician.

Between eczema, diaper rash, heat rash, roseola or hand, foot and mouth disease, rashes can crop up seemingly out of nowhere—and may sometimes be related to a viral infection. Any type of red, bumpy, itchy or irritated skin on your baby should warrant closer inspection and a search for a possible cause.

In some cases, a rash may be situational, like with diaper rash or heat rash (occurring when the sweat gland pores of young babies become blocked and sweat can’t escape), or drool rash, which is a reaction to excess saliva (often seen when teething).

Eczema is a chronic condition which can flare up based on certain triggers, such as dry, cold air, but also sweating and overheating.

But viral rashes, such as roseola or hand, foot and mouth disease, may appear alongside other symptoms, like a cold or fever. If you notice a new rash on your child, or if your child gets a rash before, during or after a fever, reach out to their pediatrician for advice.

If you have a child under 2 years old, it’s important to know about RSV. Though respiratory syncytial virus (RSV) typically presents as a mild upper respiratory cold, in kids under 2 years, it can be more serious. It can also be more severe for those born prematurely or with chronic health conditions or otherwise weakened immune systems. In severe cases, RSV can progress to a lower respiratory illness, such as bronchiolitis or pneumonia, which may require hospitalization. A new RSV therapy may soon be available to prevent severe disease—ask your pediatrician.

Symptoms of the virus often start out as mild, with just a clear runny nose and reduced appetite for a couple of days, and then progressing to cough and wheezing. Here’s what to look for.

In very young babies, the only symptoms may be decreased activity, reduced appetite, irritability and some difficulty breathing. RSV may sometimes present with a fever, but not always. Most kids are over the illness in about two weeks, but it can have serious health implications for some infants, especially those who are premature or have other health conditions.

If you notice your baby’s skin and chest are pulling in with every breath they take, you should seek medical attention right away. Short, shallow or rapid breathing, coughing, lethargy and not eating as they usually do are also red flags.

Related: 12 things parents need to know about RSV

If RSV progresses, the second stage may be marked by more serious symptoms.

Be sure to head to the nearest hospital if your child is having trouble breathing or experiencing severe symptoms.

To minimize the risk of sudden infant death syndrome (SIDS), which can be elevated until baby turns 1, but is highest in the first 6 months, babies should always be placed on their backs for sleep on a flat surface with only a fitted sheet, AAP notes. Remove any loose swaddles, blankets or toys from their sleep space, and aim to keep the room on the cooler side. Read up on AAP’s latest sleep safety guidelines for the full list of recommendations.

Related: 14 science-backed ways to reduce SIDS risk in babies

Spit up is a common occurrence in the first year, and while it might seem alarming, know that a little spit up here and there rarely bothers babies. If you’re worried about how much milk they’re ejecting, it can be helpful to recognize that a teaspoon of spilled milk tends to appear much larger in volume than it actually is (phew!). But also know that frequent or excessive spit up can be a sign of other conditions, like reflux.

Be sure to talk to your child’s pediatrician if you’re concerned about how much your child is spitting up after feeding, but here are a few ways to try to prevent spit-up.

Always contact your pediatrician if your baby vomits forcefully after most feedings or if you notice blood in your baby’s vomit. (Blood in vomit may appear bright red, or it may be dark brown and grainy, like coffee grounds.)

Related: How to choose an organic baby formula

If your little one seems fussier than usual, has reddened cheeks, extra saliva and stuffiness (and diarrhea from all that extra saliva), or even a mild fever, they might be cutting their first teeth. Many babies start teething between 4 and 7 months. This is a milestone moment, to be sure, but it’s not one of the most enjoyable. Teething hurts—and your baby will likely (loudly) let you know. Luckily, there are a few baby-safe ways to help reduce teething pain.

Related: What NOT to Do When Your Baby is Teething

Thrush is a highly common yeast infection caused by an overgrowth of a species of Candida that can be somewhat challenging to resolve. Most often, thrush infects the mouth, but it can also affect folds of skin and the diaper area. You might see white or yellowish patches on your baby’s tongue or the inside of the cheeks or roof of their mouth. Because thrush can make it painful to swallow, your infant may not want to feed as frequently, and thrush in the diaper region can make a case of diaper rash much more painful, too. Your pediatrician may prescribe an antifungal medication to help treat the infection, which tends to then clear up within 2 weeks.

However, it’s important to note that thrush can often be passed back and forth between the breastfed infant’s mouth and the mother’s nipples—which means a breastfeeding mother may also need medication treatment, and thrush can linger on pacifiers and bottles. It’s important to sterilize anything your baby has touched with their mouth to help control the infection.

The list of vaccines your child should receive in the first year list might seem long, but know that even at 2 months, your little one’s body can handle it—vaccines do not overwhelm their immune system. Rather, vaccines support your child’s immune system by helping it fight off deadly yet preventable diseases that might otherwise overwhelm them. Vaccines use tiny amounts of antigens to help your baby’s body recognize and fend off serious disease. If you have other questions or concerns, be sure to speak with your child’s pediatrician.

To help make your little one more comfortable during vaccinations, aim to start breastfeeding or bottle feeding just before the shot happens and during the shot administration. The suckling action is soothing and can provide some pain relief for babies, as can the sweetness of breastmilk or formula.

Related: Want tear-free shots? The Shotblocker and Buzzy Bee can help

Your infant may need to take vitamin D drops, depending on whether your baby primarily drinks breast milk or formula. All formulas are required to include enough vitamin D to meet your baby’s needs, so as long as they drink at least 32 ounces of formula daily, you don’t need to supplement with extra. But vitamin D is not efficiently transferred through breast milk, so if baby is exclusively breastfed or combo-fed with some breastmilk, they will need additional vitamin D, usually in the form of oil-based drops. Speak with your child’s pediatrician for more guidance.

Once your baby is over 6 months, and even though they’re starting solids, they should still be taking vitamin D, and in some cases, supplementing with iron and omega-3 fatty acids may also be helpful. Of course, if you’re considering giving your baby any supplement, always chat with your pediatrician first.

Related: Do I need to give my baby vitamins? A dietitian shares what you need to know

Babies spit up a lot, but if it’s true vomiting, it’ll be a forceful reflex and will likely coincide with some tears. Reach out to your child’s pediatrician to try and identify the cause, whether it’s something they ate or an infection.

Related: 11 expert-backed ways to prevent car sickness in kids

You and your baby likely have a lot of firsts coming up this year, from baby’s first appeared-out-of-nowhere rash to their first fever. It can be hard to know what the next right step is, but remember, mama, trust your instincts. If you’re worried about any aspect of your baby’s health, no matter how seemingly insignificant, reach out to your child’s pediatrician. As a trusted healthcare provider, they can assuage your fears and help you find early treatment if necessary. You don’t have to wade through all the unknowns alone.