Hello. You didn t mention about the birth of baby. If it was normal and the problem started afterwards then may be baby has got some infection like pneumonia. If baby was premature and cry was late then may that s because of surfactant deficiency in lungs . Either way you have to seek urgent advice by showing him to pediatrics specialist because examination of baby plus full detailed history is vital for diagnosis. For now keep him warm and feed him well. Look for any anomaly of mouth like cleft palate or abdominal swelling. Also note the fever and feeding difficulties and weight of baby. Hope that answer the question. Thanks