My son 15 month, screams at night at every hour, and in day he is very active. doctor told us he is fit, but why is he crying in sleep?

If normal toddler...: Babies more than 3 months old can be trained to sleep all night. A normal toddler (pediatrician can help verify normalcy) should be fine from bedtime (9:00) until breakfast (7:00) the next morning. Parents can do the same relaxing bedtime routine each evening. Put the baby in the crib, say goodnight, and walk away. He might wake up off and on and cry but will soon learn to fall asleep by himself.

Night Terrrors: If you find that he will not waken with your light touch, but continues to scream, this is not a nightmare but a night terror.It is similar to sleep walking or talking as a sleep disorder & often reflects poor sleeping habits & a sleep deficit. Re arranging her night routine & getting as little as a half hour more of sleep/24hrs may end this problem.Otherwise visit your dr for other suggestions.