One of the most challenging aspects of infant care is to know if an infant is sick or not. Infants are unable to tell us verbally how they feel, so we must rely on their actions. Often, what a baby does not do is as important as what s/he does. For example, an infant's appetite, or lack of one, can be an indication of how a baby is feeling. When babies are feeling ill, they will not feed as often or consume as much, whether it be due to fever, nasal congestion (babies need their noses cleared to breathe easily), or something more serious.

If a baby doesn't eat well, s/he is becomes at risk of dehydration. In this condition, the body does not have enough fluid to supply nutrients to the different organs, such as kidneys or skin. Infants who are dehydrated will appear less active than normal, have fewer wet diapers, and have cool or clammy skin. Their lips may appear dry, and they may not produce tears when they cry. As dehydration progresses, the baby will become very sleepy and difficult to arouse. These are signs of severe dehydration and warrant immediate medical attention. If the signs of dehydration are recognized early on, it may be treated with a brief visit to the doctor's office or emergency room.

It's important to recognize other signs, besides poor feeding, that place a baby at risk for dehydration. The most common cause of dehydration in childhood is diarrhea. A baby may drink a normal amount of milk but have increased loss of fluid, due to diarrhea, and become dehydrated. More frequent feedings can help prevent dehydration, but keep an eye, in conjunction with your physician, on the baby.

Babies can also lose fluid from vomiting. Babies often "spit up" after feeding, but vomiting is very different. It is usually more forceful in nature and larger in volume. Spitting up often occurs right after a feeding, while vomiting can occur at any time. Vomiting can cause dehydration or be a sign of serious dehydration. The presence of blood or greenish fluid (called bile) in the emesis is a red flag for medical attention immediately. Vomiting may be the result of dehydration, intestinal blockage, or infection.

A common sign of infection is fever. The best way to take your baby's temperature is with a rectal thermometer placed in the rectum. Using thermometer strips on the forehead and touching to determine temperature are not reliable ways to learn of a fever. In babies less than 3 months of age, a temperature greater than 100.5 may be a sign of a potentially serious infection, so you should call your doctor immediately. A fever doesn't always indicate a serious infection, but in infants it is very hard to distinguish serious from not-so-serious infections. A fever is a sign that the body is fighting an infection, which makes a fever every now and then a good thing. However, the cause of the fever should be investigated.

A good clue to your baby's health is his or her appearance and actions. A sick baby is too tired or sleepy to eat and is not active, smiling, or babbling. The sicker the baby is, the less s/he will do and the sleepier s/he is. Many illnesses in childhood have some of these features, but there is one that deserves specific mention, bacterial meningitis. This is a devastating infection of the tissues that line the brain. Children with bacterial meningitis often have many of the symptoms noted above - fever, poor feeding, decreased activity, and vomiting. The infant's "soft spot" may feel tense or even hard. This is an extreme medical emergency, and the baby needs to be examined in a hospital right away. If diagnosed and treated in time, the serious complications can be avoided, but time is of the essence. Fortunately, the Hib vaccine has prevented many cases of bacterial meningitis. With the introduction of the vaccine against the bacteria called pneumococcus, even more children will hopefully be saved from bacterial meningitis.

There is no substitute for good medical judgment, and you should always call your doctor whenever you have a question about your baby. As vaccines demonstrate, however, prevention is the best medicine. Pay attention to the early signs of any behavior that seems uncommon - you could prevent a problem, be it infection or something else, from getting worse.