How To Know When Your Baby Is Sick  


As cute and cuddly as babies are, they of course get sick from time to time. This can be an anxious, nerve-wracking time for parents, especially new ones. Should they take their baby to the doctor? Should they wait it out and see if he/she gets better on their own? Is it just gas or teething or something really serious?

Lauren Adler_02R WEB72

Lauren Adler, MD, FAAP

At Westchester Health Pediatrics, we’ve taken care of thousands of babies (and their parents) over the years and know how important it is for parents to be able to recognize the signs that their baby may be sick. We pass them along here in hopes that they can give parents everywhere some peace of mind as well as timely information.

Does your baby have a fever?

  • Anything over 100.4 F is a fever.
  • Any fever in a baby under 3 months old should be checked by a doctor as soon as possible.
  • Any temperature over 101°F in a baby under 6 months old also should be checked by a doctor as soon as possible.
  • If your baby is over 6 months old with a fever, you can observe and see how he/she is the next day.
  • A fever is the body’s way of combating infection and if not too high, is actually a good thing. If your baby is not suffering too much, resist the urge to administer fever reducers and instead, let the fever break on its own.
  • Fever is not dangerous for your baby. If your baby is older than 6 months old and still taking in fluids, is not acting listless and is not crying a lot, you don’t need to rush to the doctor.

Is he/she dehydrated?

This is another key sign to look out for because dehydration can be serious. Since your baby can’t tell you what’s going on, parents need to be very observant because the effects of dehydration can escalate quickly in babies under 2 years old.

The easiest dehydration symptom to spot is the number of wet diapers. If your baby is passing hardly any urine, or the urine in the diaper seems very dark and concentrated, he/she may be dehydrated.

Other things to check include:

  • Moistness of the mouth (should not be dry)
  • If baby is floppy or listless
  • If the fontanelle (soft spot on the top of the head) seems especially sunken
  • If the baby has no tears when crying

If a baby is not drinking milk (either breast milk or formula) or is having diarrhea or vomiting, the chances of him/her becoming dehydrated are high and parents should head to the doctor as soon as possible. Babies that are severely dehydrated may need to have IV fluids.

Is there a rash?

Since rashes can be a sign of serious illnesses like meningitis, it’s understandable that they can cause anxiety in parents. However, there are also many viruses, allergies and non-serious conditions that can cause rashes in babies.

What we tell our parents is that if a rash is accompanied by a fever, they should seek medical advice, especially if there is a purple or bruise-like rash on the baby.

Another common cause of viral rashes is roseola, a mild virus which causes babies to have a high fever and be irritable for a few days. When the fever stops, a red, blotchy rash breaks out. Rashes are also symptoms of measles and rubella which can have complications, so if in doubt, take your baby to your pediatrician.

Is your baby listless, whiney or unresponsive?

This is usually a giveaway that baby is very sick, particularly when accompanied by a fever. If your baby is under 3 months old, you need to head straight to the doctor.

Persistent diarrhea

Diarrhea can cause dehydration which can be serious in a small baby. Diarrhea can cause a temporary lactose intolerance which can lead to ongoing diarrhea for a few weeks after a stomach bug.  If this is the case, see your doctor who will probably advise stopping all dairy for a day or two.

Abnormal crying

This one can be a tricky sign to read for parents. If your baby cries when getting vaccinations, you know how he/she sounds when in pain. A high-pitched, moaning cry or whimpering can be a sign of meningitis, which is very serious. As a rule of thumb, if the crying does not sound normal to you, seek medical attention immediately.

Trust your instincts

Most of the time, parents can sense when something is wrong with their baby. If you have any concerns at all, you should always contact your pediatrician–this is what we’re here for.

How to take your baby’s temperature

At Westchester Health Pediatrics, we recommend taking your baby’s temperature rectally, the most accurate way. Here’s how:

  • The normal range for a temperature taken rectally is 97.9°F-100.4°F
  • Using a digital thermometer, lay your baby on his/her back and bring the knees up over the abdomen
  • Make sure the thermometer is clean, then dip it in water-soluble jelly
  • Insert the thermometer into your baby’s rectum, about 1 inch
  • Wait for the thermometer to take the reading (usually indicated by a beep)
  • Clean the thermometer after each use with soap and water or rubbing alcohol

When to take your baby to the pediatrician

Contact your pediatrician right away if you notice any of the following signs:

  • rectal fever above 100.4 for babies younger than 2 months
  • rectal fever of 102 or higher for babies older than 2 months
  • fever lasting more than 48-72 hours
  • crying inconsolably
  • listless or limp
  • having convulsions (seizures)
  • swelling of the soft spot at the top of the head (fontanelle)
  • pain
  • purple splotches on the skin, or another type of rash
  • pale
  • problems breathing
  • refuses to breastfeed or drink from a bottle
  • has trouble swallowing
  • persistent vomiting or diarrhea

Want to learn more about how to tell if your baby is sick? Come see us.

If you’re wondering whether your child is truly sick or just merely a little under the weather and how to tell the difference, or if you have any other questions relating to your child’s health and well-being, please come in to see one of our Westchester Health Pediatrics pediatricians. Together, we’ll discover what’s going on with your child and decide on the best course of treatment, if needed.

By Lauren Adler, MD, FAAP, Lead Pediatric Physician with Westchester Health Pediatrics, member of Northwell Health Physician Partners

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About the Author: ML Ball