Children usually cry excessively when their demands aren’t met. If your child is making a genuine demand, try and fulfil that. But keep in mind to always analyse what the child is demanding. If you keep fulfilling all their demands, they will know that they just have to cry and things will be done. If your child has developed a habit of always crying while demanding things, you should consult a psychologist for therapy.
If you observe that while crying, your child becomes breathless and undergoes some colour changes (bluish discolouration) on the face or body, it is better to consult your child’s paediatrician for proper examination.