Foreign body. Atelectasis is common in children who have inhaled an object, such as a peanut or small toy part, into their lungs. Narrowing of major airways from disease. Chronic infections, including fungal infections, tuberculosis and other diseases, can scar and constrict major airways. Tumor in a major airway.
He'll be placed on blood thinners to break up the clots...which can take from days to weeks. This is also a very dangerous time for him, as a clot could travel and lodge in a coronary artery on his heart, causing a heart attack, or it could travel and lodge in an artery in his brain causing a stroke.
Sucking on a straw can loosen the blood clot and delay healing. After the first day, gently rinse your mouth with warm salt water several times a day to reduce swelling and relieve pain. You can make your own salt water by mixing 1 tsp (5 g) of salt in a medium-sized glass [8 fl oz (240 mL)] of warm water. Do not rinse hard. This can loosen the blood clot and delay healing.