What should you know about a lump on the finger under the skin?

A smooth lump near a finger joint may be a fluid-filled cyst, while a thickened area along a tendon can affect bending or straightening. A firm bump after an injury may reflect healing tissue or a joint-related change. Redness, warmth, tenderness, and drainage suggest skin inflammation or a boil. A persistent sore or changing surface should be examined; Basal Cell Carcinoma can produce a non-healing skin lesion, but a lump is not enough to identify its cause. The exact position relative to the nail, joint, and crease helps the clinician narrow the possibilities.

Do not crush, puncture, or try to pop the lump. Avoid repeated pressure and note whether gripping, typing, or bending changes the symptoms. Record any injury, bite, splinter, manicure, or cut before it appeared. Arrange an appointment if the lump persists, enlarges, returns, causes pain, or restricts movement. Keep any broken skin clean and covered. A clinician may examine sensation, circulation, joint motion, and the surface before deciding whether imaging or treatment is needed.

Seek prompt care for rapidly increasing swelling, severe pain, spreading redness, pus, fever, numbness, blue or pale colour, or inability to bend or straighten the finger. A deep cut, bite, or puncture followed by swelling also merits quick review. Urgent assessment is especially important when pain and restricted movement progress together.

Ask whether the lump is connected to the joint, tendon, nail, or skin, and whether movement or pressure is aggravating it. Ask what changes should prompt review and whether observation, drainage, removal, or a steroid injection into the skin fits the diagnosis.