At 4 months old, your baby cannot take any over-the-counter cold or congestion medicine. The FDA warns that cough and cold products containing decongestants or antihistamines should never be given to children under 2 because of the risk of serious, potentially life-threatening side effects. Manufacturers have since relabeled these products to say “do not use in children under 4 years of age.” That means the tools available to you are simple, safe, and surprisingly effective: saline drops, nasal suctioning, humidity, and positioning.
Saline Drops and Nasal Suctioning
Saline nasal drops are the single most useful thing you can give a congested 4-month-old. They loosen thick mucus so your baby can breathe and feed more easily. To use them, lay your baby on their back in your lap with their head facing up. Place three or four drops in one nostril, wait a moment, then repeat on the other side. If your baby squirms (and they will), having a second adult hold them steady makes this much easier.
After the saline has had a few seconds to work, you can suction the loosened mucus out. Two main tools exist for this: the traditional bulb syringe and the nasal-oral aspirator (a tube device where you provide the suction with your mouth through a filter). A randomized controlled trial comparing the two found that parents strongly preferred the nasal-oral aspirator, with satisfaction rates of 94% compared to 69% for the bulb syringe. The nasal-oral aspirator also caused fewer problems: adverse events occurred in about 18% of cases versus 50% with the bulb. Both tools cleared mucus equally well, so the practical difference comes down to comfort and ease of use.
Whichever tool you choose, squeeze the air out of a bulb syringe before placing the tip in your baby’s nostril, never while it’s inside the nose. Suction before feedings so your baby can breathe while eating, and before sleep to help them settle. You don’t need to suction constantly throughout the day. A few times daily, paired with saline, is typically enough.
Cool Mist Humidifier
Dry air thickens mucus and makes congestion worse. Running a cool mist humidifier in your baby’s room adds moisture to the air and helps keep nasal passages from drying out. The AAP specifically recommends cool mist over warm steam vaporizers because vaporizers pose a burn risk if your baby gets close to the steam or if the device tips over.
Place the humidifier near the crib but out of reach. Clean it regularly (every one to two days) to prevent mold and bacteria from growing in the water tank. If you don’t have a humidifier, sitting in a steamy bathroom for 10 to 15 minutes while running a hot shower can provide temporary relief before bedtime or feedings.
What Not to Give Your Baby
The list of things to avoid is longer than the list of things that help. Camphor-based chest rubs like Vicks VapoRub are not recommended for children under 2. These products can be absorbed too easily through an infant’s thin skin, and there’s evidence from animal studies suggesting they may actually worsen breathing difficulties in young babies rather than improve them. This is especially concerning for small or preterm infants.
Essential oils like eucalyptus and menthol fall into the same category. Even diffusing them near a young infant carries risk because their airways are narrow and reactive. Honey-based remedies are off-limits until 12 months due to the risk of botulism. And again, no decongestants, antihistamines, or cough suppressants of any kind.
Safe Sleep With Congestion
It’s tempting to prop up one end of the crib mattress so your baby sleeps at an incline. Don’t. The CDC and AAP are clear that infants should sleep on a firm, flat surface, not angled or inclined. Wedges, pillows, and rolled towels under the mattress all increase the risk of your baby sliding into an unsafe position. Instead, do a round of saline and suctioning right before putting your baby down. That’s the safest way to help them breathe easier while they sleep.
If Your Baby Also Has a Fever
Congestion with a mild fever often signals a common cold, but age matters here. Fever in a baby under 12 weeks old requires immediate medical attention because it can indicate a serious infection. At 4 months, your baby is just past that threshold, but you should still contact your pediatrician before giving infant acetaminophen. The AAP recommends checking with a doctor before giving acetaminophen to any child under 2 to make sure the dose is correct for your baby’s weight.
Signs That Need Medical Attention
Most infant congestion is caused by a virus and clears within a week or two. But certain breathing patterns mean your baby is working too hard to get air and needs to be seen right away. Watch for fast, shallow breathing that doesn’t slow when your baby is at rest. Look at the spaces between and below the ribs: if the skin pulls inward visibly with each breath, that’s called retracting, and it signals respiratory distress. Nostrils that flare wide open with each breath and grunting sounds on exhale are also warning signs.
Other reasons to call your pediatrician include congestion lasting more than 10 to 14 days, refusal to feed, significantly fewer wet diapers than usual, or a fever above 100.4°F (38°C) that persists. A congested baby who is still eating, sleeping in reasonable stretches, and having normal wet diapers is usually doing fine with home care alone.