What is reflux?  
Reflux is swallowed food coming back up on the food pipe and sometimes even in the mouth. The reason for this is that the valve (which helps to keep swallowed food in the tummy) where food pipe joins the stomach is still developing. The reason for under-development of this valve is not precisely known; it is associated with immature digestive system, genetic factors, food intolerance and other health conditions. 
If your baby has reflux, the milk or food in his stomach mixed with stomach acid can come up her baby's mouth. This may even cause vomiting. Most of the time this happens after feeding. However in some cases, this may occur when your baby coughs, cries or strains. In some cases, foods don't come up to their mouth and stay in his food pipe. This is referred to as silent reflux. It is harder to diagnose this type of reflux and thereby more damage is done. 
Even though reflux is a common problem, it causes discomfort for families. The reason is that it affects the feeding, sleeping, growth, and behavior pattern and life quality of your baby. It may also cause inconvenience in your daily life. When your baby is around 12 and 18 months old, the valve at the end of the food pipe will get stronger and most probably your baby will get better or completely grow out reflux on his own. Almost half of the babies have reflux in their first 3 months but when they are around 10 months old, reflux rate will drop to 5%.
How will I know my baby has reflux?
 What you should do is following the signs. Just watch out for the following after you breastfeed your baby; 
- Some milk comes from his mouth
- Baby is cranky, cries and shouts
- Hiccups repetitively
- Starts coughing (when the milk coming up to his mouth gets into his trachea)
- Is usually irritable and in pain after eating
- Baby is vomiting
- Has a hoarse or rusty voice
- Even though he is hungry, he stops eating after a short while and starts crying
- His back is tense like a bow and he draws back himself while being breast-fed
- Starts crying during his sleep and wakes up frequently after eating
- has breathing related problems (is short of breath, wheezes, coughs, has recurring chest infections)
- has development disorders
- Suspicious recurring ear, throat, sine infections. 
How can I prevent reflux?
Keep calm; it’s not the end of the world. Most babies with reflux stay healthy and happy even if they vomit. If your baby does not have a serious discomfort, you don't need to follow a special treatment. You just need to know that your baby will grow out of reflux in time. You don't need to take your baby to a doctor in a rush.
You may try the following to help and support your baby during this period: 
- Hold your baby upright for 20 minutes after each fed.
- You may walk him around with an infant carrier for a while without shaking him.
- Feed your baby with smaller portions and more frequently.
- If he vomits after being fed, instead of re-feeding him wait for the next nursing time.
- If you bottle-feed your baby, burp him up every 2-3 minutes during feeds.
- Try raising the head end of your baby's bed/cradle when laying him on his back after fed.
- Try using a pacifier.
- Be careful not to shake, move and sway your kid too much. - Plan the schedule of your baby in a way that you feed him after he wakes up not before he goes to sleep.
- Change diapers before feeding him, when his stomach is empty. Raise the head end of the place you lay your baby to change his diapers. Do not lift his legs too high while changing his diapers.
 - Do not make him wear clothes that are too tight at the tummy part and do not tighten the diapers too much.
- If you are breastfeeding, avoid eating acidic foods like citrus, tomatoes, fatty, spicy, bitter foods, chocolate and carbonated drinks. 
When should I take my baby to a pediatrician?
If your baby has reflux problems more than 5 times a day; if she cries a lot after each fed and vomits regularly, you should consult your doctor. 
Also you must take your baby to a doctor if; 
- her vomit has blood in it
- she is anemic
- she has difficulty in swallowing
- she has breathing related problems (short of breath, wheezes, coughs, recurring chest infections)
- She has problems in development and is not gaining weight
-She has recurring ear, throat, sine infections.
How is reflux treated?
If your baby's reflux is troublesome and causes severe health problems, your doctor may recommend the following: 
- Your doctor may suggest adding a thickener to the milk you will feed your baby.
- Your doctor may suggest adding wholegrain to make your baby's milk thicker.
- Trying an anti-acid may be suggested.
- If your baby is not gaining weight, a higher calorie diet may be suggested or in more serious cases tube feeding may be recommended. 
Reflux symptoms are similar to symptoms of cow's milk allergy and lactose intolerance. If you breastfeed your baby, try avoiding cow's milk and other dairy products for a few weeks. Watch and observe your little baby. If your baby is formula-fed, your doctor may suggest another hypoallergenic formula.