Transferrin saturation is a calculated value resulting from a medical laboratory test to measure the amount of iron bound to transferrin in the blood. The liver produces transferrin, which is a protein that serves to bind iron molecules and carry them through the bloodstream to the bone marrow.
In addition to the cough, your child may also have a hoarse voice and have laboured breathing. Croup is most common in autumn and winter, and when a child is between 6 months and 3 years old. However, older children up to 15 years old sometimes get croup too. Croup is a common respiratory condition in children caused by either a viral infection or allergy.
1 Croup is an infection of the larynx, trachea, and the bronchial tubes usually caused by viruses. Less frequently, croup may be caused by bacteria.  Croup is contagious, especially during the first few days of the illness.