Laryngomalacia: This is the most common cause of hoarseness in infants, characterized by soft and pliable cartilage of the larynx that can cause partial airway obstruction when inhaling. It typically presents in the first few weeks of life.

Vocal Cord Nodule or Polyp: Although less common in infants, these can cause hoarseness due to the abnormal growths on the vocal cords.
Acute Laryngitis: This can be caused by viral or bacterial infections, leading to inflammation of the larynx and resulting in hoarseness.
Gastroesophageal Reflux Disease (GERD): Stomach acid reflux can irritate the vocal cords, leading to hoarseness.

Congenital Subglottic Stenosis: A narrowing of the subglottic airway that can cause respiratory distress and hoarseness. Early diagnosis is crucial for appropriate management.
Vocal Cord Paralysis: Can be unilateral or bilateral, resulting from nerve damage, which may be congenital or acquired. This condition requires prompt identification and treatment to prevent long-term complications.
Foreign Body Aspiration: Although more commonly associated with choking or coughing, a foreign body in the airway can also cause hoarseness and is a medical emergency.

Papillomatosis: A rare condition caused by the human papillomavirus (HPV), leading to benign tumors on the vocal cords and potentially causing hoarseness.
Laryngeal Web: A congenital or acquired condition where a web-like tissue forms across the vocal cords, which can cause hoarseness and breathing difficulties.
Laryngitis due to Inborn Errors of Metabolism: Certain metabolic disorders can lead to laryngeal inflammation and hoarseness, though these are exceedingly rare.