I have four little ones and I'd like to know how old your baby is, newborns usually cry for a specific reason, it is their only way to communicate with you. Also you should be able to tell what your baby is trying to tell you from their cry, is he tired? is he hungry? does he have gas, or does he sound like he is in pain? trust your instincts no one knows your baby better than you.

I have a daughter who is 2 1/2 months old. I have often wondered the very same thing that you are asking.

Personally, I believe you can tell the difference between when a baby is just crying to when there is something wrong. I think once the crying crosses over into an urgent, obviously upset cry, you've left them too long and should go get them at once. But if your baby is crying and doesn't seem panicky, I do think it's okay to let them cry for 5-10 minutes. My pediatrician had told me never more than 15 minutes, but I get uncomfortable with it at about the 10 minute mark. Once again, alot depends on the type of crying that your baby is doing for that period of time.

A baby does need to cry sometimes to exert energy.

One thing you may find helpful is the Dunstan Baby Language system. It is helpful for determining why your child is crying when you are unsure. It goes off of 5 basic "syllables" that you can hear in your baby's cry. "Neh" means the baby is hungry (your baby's tongue will also be curved upward against the roof of their mouth), "Eh" means the baby needs to burp, "Eairh" means your baby has gas, "Owh" means your baby is tired (you will know this one because your baby's mouth will be in a perfect O shape), "Heh" means your baby is uncomfortable (i.e. too hot or cold).

I know that my daughter will most often cry for 2 basic reasons. Hungry, or tired. If I know she's full (and if she doesnt' "root" when I rub her cheek) then I swaddle her and rock her and typically that helps her fall asleep. Some babies struggle to sleep on their own.

I know it can be frustrating to know how long to let your baby cry. I do believe that some times you do just need to let them cry because they do need to learn to comfort themselves and fall asleep without you constantly rocking them, etc. But I would say from personal experience to never let it exceed 10 minutes or 15 at the very most, and once again, go sooner if the cry becomes urgent, angry, panicky, or the baby is holding their breath between screams.

Hope this was helpful.

You shouldnt let a baby cry a long period of time. Whenever your baby cries you should always respond to it immediatly. =]]

Everyone says to let your baby cry, but keep in mind that this is the only form of communication the child has. Self soothing takes awhile to develop and some statistics suggest that letting your child cry it out does not help them develop this any faster, as a matter of fact it may make it a longer process. Until a baby is older, it does not typically just cry for someone to pick it up, contrary to popular belief. If the child is crying hard or even if only lightly for a minute or two, I suggest checking in. Sometimes, the longer you let the child cry the more upset the infant can become and soothing is even more difficult. However, if the baby is older, consider a mobile or something to help calm the child. If nothing is wrong, give it a twist or whatever and see if this helps. If the baby is still crying this can be a sign of many things. Either way, you are the parent and only you know how long to let your baby cry. They are all different and you know your baby better than anyone. Good luck!