What are the signs of reflux in a 5 month old?

What the evidence says

Spitting up a little milk after feeds is very normal for a 5 month old. Doctors call this reflux, or GER for short. It happens because the valve between the stomach and the tube leading to it (the esophagus) is still maturing, so milk can come back up easily.

Plain reflux usually does not bother the baby much. Signs include burping up small amounts during or after a feed, occasional wet burps, and otherwise being content, feeding well, and gaining weight normally.

The signs that suggest something more, called GERD, are different. Watch for poor weight gain, frequent crying or fussiness during feeds, arching the back or twisting away while eating, choking, gagging or coughing with feeds, refusing to feed, or trouble breathing. These can mean the reflux is causing real discomfort.

A Canadian source notes that irritability, crying, and back arching can sometimes just be normal baby behaviour, not reflux at all, so these signs alone don't confirm GERD. A doctor looks at the whole picture, including growth and feeding, to tell the difference.

Most babies outgrow spitting up by the time they start eating solid foods, and it rarely needs medicine. If you're seeing the more worrying signs above, especially weight loss or breathing trouble, it's worth a call to your child's doctor rather than waiting.