Most babies vomit small amounts from time to time and bring up some milk when they burp. This is known as possetting and is usually nothing to worry about. You can tell when your baby is vomiting rather than posseting because there will be a lot more coming out.
Vomiting is also very common (up to half of all babies) and in most cases will resolve with time. Although it might look like they are vomiting a lot, most babies continue to grow normally and do not look particularly distressed.
As long as your baby seems otherwise healthy and continues to gain weight, there's usually no need to worry or seek further help.
If you are breastfeeding, seek advice from a breastfeeding specialist, either a specially trained health visitor or a breastfeeding counsellor. It is possible that your baby is not latching properly.
If you are bottle feeding, ensure your baby is in the right position (sitting almost upright) and that you use the recommended amount of powder (it is quite easy to use too much if you have changed product, or using a different scoop than the one provided in the tin).
It is also quite easy to give your baby too much milk when you are bottle feeding. Their stomach is only small and most babies need little and often: 6-7 feeds per day is the norm, including at night. Your health visitor can help review how much milk you baby should need and the timing of the feeds.
More information is available on the baby centre website.
If all the above measures are not working there are some evidence that thicker or thickened formula may help, so you could try to change the formula (your pharmacist should be able to advise you). However, if after 2 weeks you are still concerned, seek advice from your GP.
Possible causes of excessive vomiting include:-
This is usually nothing to worry about if your baby was well before he vomited. It may happen when the force of vomiting causes tiny tears in the blood vessels lining the food pipe, or if you are breastfeeding, your nipple(s) are bleeding.
However, call your GP if your baby continues to have blood in their vomit or if the amount is increasing. They will probably want to see a sample of the vomit if it contains blood or bile, so, although it may be an unpleasant task, try to save some. Green bile can indicate that your baby’s intestines are blocked, a condition that needs immediate attention.
If you're worried that your baby has problems with cow's milk, there are steps you can take. If you breastfeed your baby, you could try cutting cow's milk from your diet for 2 weeks. If your baby is formula-fed, trying a hypoallergenic formula may help.
Talk to your doctor before trying these, though. They will check your baby's symptoms first, so they can be sure of what's causing them.
Your baby may be vomiting because they have an infection. This is usually associated with a temperature above 38°C / 100.4°F. Although the most likely cause is a viral infection, other causes include urinary tract infections or very occasionally a more serious illness such as meningitis or sepsis. Signs of a serious infection include:
Your child needs urgent help if any of these features are present - go to the nearest hospital emergency (A&E) department or phone 999.