Summarize this article:

Remember that crying is one of the only forms of communication that an infant can access, and it is a consistent indicator of need. Put yourself in the mindset of the child and consider what could be causing discomfort. Some common reasons that babies cry are:  Hunger:  Most newborns require feeding every two to three hours around the clock. The need to suckle: Infants have a natural instinct to latch and suckle as this is how they derive nourishment. Loneliness. Babies require social interaction to develop into happy, healthy children and will often cry when they want affection. Tiredness. Newborn infants need frequent naps, sometimes sleeping as much as 16 hours of the day. Discomfort: Think about the context of the crying episode and what your child's experience may be in order to anticipate normal needs and desires. Over-stimulation: Too much noise, movement or visual stimulation can overwhelm infants, causing them to cry. Illness. Often the first sign of illness, allergy, or injury is that the infant cries and does not respond to soothing. Unlike the guessing game we play with infants, children have access to more sophisticated forms of communication and we can ask, "What is wrong?" This doesn't necessarily mean that they are capable of communicating like adults, though, so it's important to ask simple questions and read between the lines when a child seems unable to describe a problem in detail. Younger children can have difficulty answering questions when upset, so it is important for parents and caregivers to pay attention to the context and physical condition of the child when they are crying. If the child is hurt or unhappy, it can help to distract them from the pain until it subsides. Try to refocus their attention on something they like. Determine if and where injury may have occurred, but ask about every part of her body except for where they are actually hurt. This requires them to think about those body parts rather than the one which hurts, creating a distraction. Children often cry in response to discipline or after negative interactions with an adult or a peer. When this occurs, determine whether action is warranted to mediate the situation (e.g. put fighting children in time-out) but always remind the child they are safe and loved, in spite of conflict. All children will behave badly from time to time.  However, if the child uses crying, anger, or shouting in an attempt to receive what they want, it is important to prevent the association between bad behavior and satisfaction.  If your toddler or child is throwing a tantrum, remove the child to a quiet room and let them remain there until the tantrum passes, returning them to a social environment when the anger has passed. If the upset child is old enough to walk and follow commands, ask the child to go to their room, reminding them that they are allowed to return, tell you what they want, and why they are upset once they calm down. This also teaches the child productive coping strategies for anger and disappointment while still ensuring the child feels loved and respected.

Summary:
Know why infants cry. Ask the child questions. Notice if the child is injured. Offer distractions. Reassure the child. Time out.