There's a reason most parents don't leave the house without an ample supply of tissues. That reason? Runny noses. Sometimes it may seem like your child has a runny nose for months on end. And, in fact, he or she might — most infants who have moderate exposure to older children will experience six to 10 colds during their first year.

Colds are upper respiratory tract infections caused by one of many viruses. Your baby can become infected repeatedly by the same virus. Colds generally last a week or two, but occasionally they persist longer.

Some colds settle mainly in your baby's nose, and others may settle in your baby's chest. When your baby has a cold, he or she will likely develop a congested or runny nose. Nasal discharge is clear at first, then turns yellow, becomes thicker and may even turn green. After a few days, the discharge again becomes clear and runny. Colds may also produce other signs:

• A low-grade fever for the first few days
• Sneezing
• Coughing
• A hoarse voice
• Red eyes

Colds are mostly a nuisance and usually not a serious health risk. But take precautions when your baby has a cold because these infections can progress into more serious problems, especially in smaller or younger infants. In addition, your baby may have difficulty breathing, which, besides being uncomfortable, can interfere with nursing or bottle-feeding.

Watch for these signs of a worsening condition:

• Prolonged or rising fever
• Irritability
• Baby tugging at his or her ear
• Difficulty breathing
• Lack of usually vigorous nursing or bottle-feeding
• Unusually restless nighttime sleep
• Thick pus coming from your baby's eyes

If your baby seems to be sneezing or snorting a lot and is frequently congested, he or she may have something other than a cold. Because babies' nasal passages are quite small, it doesn't take much mucus to cause congestion. Congestion may also result from exposure to dry air and irritants such as cigarette smoke.

Colds are most commonly spread by droplets containing the virus when people sneeze or cough, or by hand-to-hand contact. You can do several things to limit the number of colds your baby has. Wash your hands frequently, and avoid taking your baby to places where people with colds may congregate.

There is no cure for your baby's cold. Antibiotics are ineffective against viral infections and can't cure, prevent or shorten the course of a cold. Vitamin C and zinc haven't proved helpful in preventing or treating colds in babies. Unfortunately parents and doctors can't help babies recover more quickly — your baby's immune system will need time to conquer a cold. But you can try to help your baby feel better despite the cold, and you can limit the possibility of the illness becoming worse.

The best thing to do is to give your baby plenty of liquids. Fluids will keep the congestion looser. Because a baby with a cold may become tired or frustrated and suck only briefly at one feeding, encourage frequent feedings. You can try acetaminophen (Tylenol Infants' Drops, others) to relieve a fever of more than 102 F (39 C) or if your baby seems uncomfortable.

Remember that coughing isn't always bad. Coughing is protective and can help clear mucus from your baby's airway. Coughs can be dry and hacking or wet, loose and productive. Sometimes your baby's coughs may come in a series (spasms), which can even result in vomiting. Coughing becomes a problem when it interferes with your baby's intake of food, activity or sleep.

Call your doctor during office hours if your baby has:

• A mild fever or a temperature of more than 100 F (39 C) for more than 72 hours
• A cough for more than 1 week
• Frequent coughing that causes vomiting
• Nasal discharge that is thick, green and lasts more than 2 weeks
• A crusty rash under the nose or mouth, which could be impetigo

Contact your doctor or get medical help immediately if your baby:

• Has difficulty breathing or is bluish around the lips and mouth
• Is not having wet diapers or won't take fluids
• Is having severe coughing with a change of skin color
• Has blood-tinged sputum

Using a vaporizer or humidifier may help keep your baby comfortable. It doesn't matter whether the air breathed is very dry or humid because the air in the lungs is fully humidified by the nose and breathing passages. However, when an infant has nasal congestion, adding extra moisture to the air can be soothing to the nose. Extra humidity can also be helpful to infants with very dry, irritated skin, such as atopic dermatitis or eczema. Follow these tips when using a humidifier:

• Change the water and clean the humidifier daily. Otherwise mold may grow, which can be spread into the air.
• Don't run the humidifier so much that your windowsills become continuously wet in cold weather.
• Don't let the steam or mist spray directly over your baby or the crib. The bedding can become damp, and your baby may become chilled.
• Don't add medications. Medications added to the air by a vaporizer or humidifier aren't necessary.
• Remember that children can be burned if they get near a hot vaporizer or steamer.

If nasal congestion makes it difficult for your baby to nurse, you can help by suctioning your baby's nose with a rubber-bulb syringe before you feed or put your baby down to sleep. Squeeze the bulb before you put the tip of the clean bulb syringe into your baby's nose. Insert the tip into your baby's nostril gently, pointing toward the back of the nose, rather than upward.

Release the bulb, and let it suction the mucus from your baby's nose. Remove the syringe from your baby's nostril and empty the contents onto a tissue by squeezing it rapidly while holding it upside down. Repeat for the other nostril. Be sure to clean the bulb syringe with soap and warm water when you're finished. If your baby is in child care, it's a good idea to supply a bulb syringe — labeled with your baby's name — to discourage sharing.

If the discharge is thick, saline nose drops or saltwater nasal spray may help loosen the mucus. Saline nose drops and sprays are made with the optimal mixture of salt and water. They're inexpensive and available without prescription. Ask your pharmacist if you can't find them.