Sebaceous Cyst Getting Bigger: What to Know

A sebaceous cyst, often called an epidermoid cyst, is an enclosed sac beneath the skin. It can enlarge gradually as keratin collects inside. Faster change, warmth, redness, tenderness, or cloudy drainage suggests inflammation or infection may be present. These features do not identify the cause by themselves, and a growing skin lump should be checked rather than diagnosed from appearance alone.

A cyst may flatten after inflammation settles while its sac remains. This is why a lump can recur after it appears to have drained. Photographing the area and noting changes in pain, colour, firmness, or discharge can help your clinician assess the pattern.

Do not pop, cut, or repeatedly press the lump. Keep it clean, reduce friction from clothing or equipment, and use a warm clean compress for comfort if the skin is intact. A clinician may recommend observation, a steroid injection into the skin for selected inflammation, drainage if an abscess has formed, or cyst removal when the sac needs to be removed.

Book a timely assessment for steady growth, a new hard or fixed feel, repeated drainage, or a lump that keeps returning. Seek urgent care if pain becomes severe, redness spreads, pus collects, you develop fever, or swelling affects nearby function. Do not delay review for a rapidly changing lump.

Ask what is driving the enlargement, whether the lump needs treatment now, and how recurrence can be reduced. Ask how to recognise infection and whether removal should wait until active inflammation has settled.