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Dr. Sears' Guide to Infant Illnesses

When new parents come into my office for their baby's first checkup, I tell them that pediatrics is a partnership between parents and doctor, and each person plays an important role. Parents need to be keen observers and accurate reporters, while a doctor must use the parents' observations to help make the right diagnosis and prescribe proper treatment.

During the first year, you'll learn a lot about how your baby communicates. Before you realize it, you'll be an expert at differentiating hungry cries from sleepy ones and wet-diaper wails from I-want-to-cuddle whimpers. You'll know your baby's sleeping and eating patterns, and the sparkle in her eyes that comes when she's happy.

Understanding when your baby is sick requires knowing her when she's well. Often a change in behavior will be the first symptom you notice, but it helps to know the signs that pediatricians look for as well. Here, a guide to some of the most common illnesses that babies encounter during the first year.


Contributing editor William Sears, M.D., is the author, along with his wife, Martha Sears, R.N., of The Baby Book.

Gastroesophageal Reflux Disease (GERD)

During the first few months, many babies experience varying degrees of GERD, which occurs when acidic stomach contents regurgitate back into the esophagus, causing pain. GERD is common in babies because the circular band of muscle that acts as a valve between the esophagus and the stomach is immature.

Symptoms: The discomfort from GERD causes babies to cry and whimper regularly, and is often misdiagnosed as colic. (I encourage parents not to even use the word colic but to call it the hurting baby. This motivates each person in the parent-doctor partnership to keep searching for why a child hurts and what to do about it.) Other symptoms include frequent spitting up or vomiting (though not all babies with GERD spit up), jerky movements like pulling the legs up or arching the back, frequent wet burps, or throaty gagging noises.

Treatment: Smaller, more frequent feedings (half as much, twice as often) can help because less food in the stomach at one time decreases reflux. Frequent feedings will also stimulate the production of saliva, which neutralizes stomach acid and lubricates the esophageal lining. Keep your baby upright for at least a half hour after feeding to help gravity hold the food down. Breastfeed if you can, since breast milk is digested faster than formula is.

When to call the doctor: With mild reflux, the simple home remedies mentioned above usually do the trick. If the GERD is severe enough to interfere with weight gain and sleep, or is causing your baby a lot of pain, the doctor may prescribe medications that block the production of stomach acid. GERD usually begins to subside around 7 months, when babies spend much of their day upright.


Most babies get several colds during their first year. Colds are caused by viral infections that make the membranes of the nose and respiratory passages swell and pour out mucus.

Symptoms: Narrowed, mucus-filled breathing passages can cause your baby to cough, wheeze, and breathe fast, and they may interfere with normal sleeping and eating patterns. Your baby may also have a low-grade fever, a runny nose, sneezing, and a decreased appetite.

Treatment: If your child is having trouble breathing, sit him on your lap in the bathroom with the shower on the hottest setting for ten minutes. The steam will help loosen the congestion. I also recommend using a nasal aspirator with saline nasal spray to suction out the secretions. Doing this before bedtime can help your baby sleep. Offer him extra fluids, and don't use cold medicines without checking with your doctor.

When to call the doctor: If your child is under 3 months, you should call at the first sign of illness. For infants older than 3 months, call the doctor if his lips or nails develop a bluish tinge, if he's having trouble breathing, or if he has a fever that warrants a call to the doctor. If your infant remains in good spirits and the nasal discharge is clear, give the cold a week on the home treatment mentioned above. If your baby's nasal discharge becomes thick and yellow, visit the doctor: She may recommend a cold medicine. Antibiotics won't work because they fight bacterial infections, and colds are caused by viruses.

Respiratory Syncytial Virus (RSV)

A common virus of early infancy, RSV can be very serious. It is one of the major causes of hospitalization for respiratory illness in children under 1 year of age.

Symptoms: RSV usually begins like the common cold, with a runny nose, low fever, and cough, but it can last for several weeks and infect the bronchial passages, causing bronchitis (if it's in the larger airways) or bronchiolitis (if it's in the smaller breathing tubes). You may also hear your child wheezing when she breathes. If RSV spreads to the lungs, it can cause viral pneumonia.

Treatment: If your baby has a croupy cough (sounds like a barking seal), try the "steam clean" home remedy described in "Colds," or take her outdoors into the damp night air for a brief period.

When to call the doctor: If your child is under 3 months, call at the first sign of illness. Take her to an emergency room if she's struggling to breathe or is wheezing. Seek medical attention if her cold lasts more than a week.

Prevention: Don't allow smoking around your baby (smoke makes breathing passages more susceptible to irritation or infection), be sure your daycare has strict policies about separating sick infants, and wash your hands frequently. If your child was born prematurely, she is more at risk of complications from RSV. Ask your doctor about Synagis, a series of preventive shots available during RSV season, which runs from fall to spring.


Often after babies start eating solid foods, they become constipated and have difficulty passing stools. It's important to treat constipation because if the hard stool is painful, your baby may refuse to go. This may then stretch the intestines, weaken muscle tone, and make it more difficult to pass the stool.

Symptoms: In a newborn, watch for stools that are firm and infrequent (less than once a day). It may be helpful to keep track of your baby's bowel movements. If you see blood on his diaper, it may be due to a rectal fissure, a tiny tear in the rectal wall caused by a hard stool. These harmless yet painful tears heal quickly once the constipation is cured.

Treatment: If you're feeding your baby formula, experiment with different brands until you find one that produces a softer stool. (Tell your pediatrician if you make a change.) If your baby is more than a year old and you recently switched from formula to cow's milk, try going back. Decrease constipating foods, such as bananas and rice cereal, in your baby's diet, and add high-fluid and high-fiber ones, such as pur[E233]ed pears and barley cereal. Offer plenty of liquids such as apple and prune juice.

When to call the doctor: If your baby seems to be in pain or hasn't had a bowel movement for more than four days, call your pediatrician. In severe cases, she may prescribe a mild laxative or an enema.


Diarrhea refers to bowel movements that are too frequent and too watery. It is most often caused by a virus but can also result from a bacterial infection, an allergy, or medication. The potential danger of diarrhea is dehydration.

Symptoms: Newborns may have up to 12 small bowel movements a day, but by 3 months, they may go a day without having any. If your infant's bowel movements become more frequent and watery all of a sudden, she probably has diarrhea.

Treatment: Talk to your doctor about administering a commercial oral rehydration solution (ORS), which restores fluids and essential electrolytes, like sodium and potassium, in approximately the same proportion that they are lost in diarrhea. Breastfed infants can continue to nurse as often as desired, in addition to consuming ORS. Keep track of your baby's stools to report to your doctor.

When to call the doctor: If your baby has a high fever, bloody diarrhea, increasing abdominal pain, or vomiting, or you suspect she's dehydrated or losing weight, she needs medical attention. Signs of dehydration are lethargy, dry eyes and mouth, and fewer wet diapers.

Ear Infections

When fluid accumulates in the middle ear, it can act like a culture in which germs grow. The infected fluid presses on the eardrum, producing intense pain.

Symptoms: Your baby might be cranky and unwilling to lie flat, and may cry during feeding and wake up during the night because of pain.

Treatment: To ease middle-of-the-night earaches, give your baby the appropriate dose of infant pain reliever. Keep him upright, so that fluid drains away from the eardrum, relieving pressure.

When to call the doctor: If you suspect an ear infection, have your doctor examine your baby's ears. If the eardrum looks infected, she may prescribe an antibiotic. It's important to seek medical help, since repeated untreated ear infections may lead to hearing loss and consequent speech delay.

Prevention: Nurse your infant if you can, since breastfed infants have fewer ear infections. Control allergens (such as cigarette smoke, dust, and animal dander) because they can cause fluid buildup in the ear. If your child has a cold, suction his nose, as described in "Colds," to prevent germs from entering the ear. If he's bottle-feeding, keep him upright to prevent formula or milk from entering the middle ear from the throat.


Fever is a symptom of an underlying illness, not an illness in itself. Like the "check engine" light on your dashboard, it's a clue that something is going on that needs attention.

Symptoms: Your baby may feel hot or look flushed.

Treatment: If your child is over a year old, seems happy, and doesn't have related symptoms such as a cough or runny nose, there's usually no need to call the doctor immediately. To lower the fever, you can give your baby the infant pain reliever recommended by your pediatrician; a lukewarm sponge bath may help as well.

When to call the doctor: When to contact your doctor about a persistent fever depends on your baby's age. The American Academy of Pediatrics' guidelines are as follows: For a baby 3 months or younger, call a doctor immediately if her rectal temperature is over 100.4°F; for an infant 3 to 6 months, over 101°F; and for a baby older than 6 months, over 103°F. Sometimes, how your baby looks is more significant than how high the fever is. Call your doctor if she is lethargic, pale, or in pain.

While infant illnesses cause babies to lose sleep and parents to miss work, it helps to view them as opportunities to connect with your child instead. Infants naturally become clingy when ill, so take advantage of the extra cuddle time. In addition to the treatments above, they need the tender loving care that only a mommy and daddy can provide.