swollen gums,gum swelling或者swelling of gum都是可以用的
都有相应的例句：
共同的迹象,不足是穷人头发和皮肤,出血,牙龈肿胀,瘀伤和坏血病.
Common signs of deficiency are poor hair and skin,bleeding,swollen gums,bruising and scurvy.
功能主治：咽喉肿痛、牙龈肿痛、火热内盛毒火聚集引发的多种病症.
Indications function:throat swelling and pain,gum swelling and pain,the fiery,Shing poisoning caused by the fire gathered a variety of illnesses.
用于热毒蕴结所致的咽喉疼痛,牙龈肿痛,口舌生疮.【用法用量】吹敷患处,每次少量,一日数次.
It is used for the swelling and pain of throat,the swelling and pain of gum,ulceration in the mouth and on the tongue due to noxious heat.