An abscess is generally easy to spot when it forms under the skin. Skin abscesses appear as swollen, red, and tender lumps that are filled with pus. The skin over and near the abscess may feel warm to the touch, and as the infection progresses, the lump may grow larger and more painful. Sometimes, you can see a white or yellow center, indicating that pus is near the surface and ready to drain. While less common, abscesses can also form internally. Abscesses that form on or inside the organs (such as the liver, lungs, or pancreas) are not visible from the outside but often cause symptoms like fever, fatigue, and localized pain. If you suspect an abscess has formed, it’s important to seek medical attention to have your symptoms assessed.