Common Reasons for Your Baby Crying Uncontrollably Teething - a very common cause of fussiness in infants age 4 months to 2 years. Signs of teething include vigorous chewing on hands or toys, drooling, and bulging gums. Your infant will have no fever and might also wake up crying at night more frequently. These screaming, kicking, crying fits are a part of typical development and allow our children to communicate their unhappiness and/or frustration about an event or response, typically when they do not get their way or something that they want. Most toddler temper tantrums last for a few to 15 minutes, and for most children, they will recover What Causes Crying for No Reason? Here is why you might be crying more than usual. Depression Depression can cause a host of symptoms, including: Sleep troubles Appetite changes Concentration issues Fatigue Loss of interest in activities Feelings of emptiness Bodily aches and pains Hopelessness Suicidal ideation 3atTG.