Both cause circular growths or lumps on the skin and can look similar. A boil looks like a large pimple—a swollen ring of red with one or more white or yellow pus-filled sores (pustules).

A boil is red or discolored, swollen, and contains pus, like a pimple. A cyst is under the skin and is usually painless but can resemble a boil if it ruptures or becomes infected. Cysts and boils ...