As weight is ok and baby is active and vitals are normal, there is nothing to worry about. It's quite common and may be due to digestion issues. Please visit a pediatrician

Based on your description, this appears to be a normal developmental behavior. At around 4 months, babies often make grunting, cooing, and other vocal sounds while playing, feeding, or stretching as they discover their voice and body movements. Since your baby is active, feeding well, and gaining weight appropriately, this is reassuring.

I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

Hello, Grunting noises in infants can be quite common, especially during feeding, playing, straining, or even while sleeping. In many babies, this happens because the tissues and cartilage of the respiratory tract are still developing and are relatively soft. Based on what you’ve described, if your child is active, feeding well, growing appropriately, and gaining weight as expected for age, this does not appear to require urgent intervention. Most infants outgrow this as their airways mature, typically by 12–18 months of age. However, grunting becomes concerning if it is associated with refusal to feed, difficulty breathing, bluish discoloration, persistent vomiting or significant reflux, poor weight gain. If any of these symptoms are present, your child should be evaluated by a paediatrician promptly. Even if your baby is otherwise doing well, do mention this to your paediatrician during the next vaccination visit so that a physical examination can be performed and any underlying concerns can be ruled out.

Hii. Since when he is making these noises? As per your description, these seems normal but I will be able to comment on these noises better only after examination and seeing video recording.

Looks normal.

Normal infant behaviour

Greetings The grunting and stretching your 4-month-old baby boy is displaying shares characteristics with normal infant behavior and is typically not a cause for concern.Since he is active, alert, and gaining weight properly at 6.2 kg, these sounds are most consistent with a maturing digestive system or him simply finding his voice.Babies often grunt or arch their bodies to coordinate muscle movements while passing gas, digesting milk, or preparing for a bowel movement.

If your baby is otherwise active, feeding well, gaining weight normally, and the grunting happens only occasionally while awake (during play, stretching, or feeding), it is usually a normal developmental behavior and not a cause for concern. Many babies make grunting or straining noises as they discover their voice and tighten their abdominal muscles. However, if the grunting is persistent, occurs during sleep, is associated with fast breathing, chest retractions, bluish discoloration, poor feeding, fever, or poor weight gain, your baby should be examined by a pediatrician promptly.

This body stretching and grunting while stretching after waking form sleep is normal only Nothing to worry