This page is educational and is not a substitute for professional medical advice, diagnosis, or treatment.
Please ask a qualified health professional about symptoms, treatment decisions, or concerns about your own condition.
Emergency? If symptoms are severe, rapidly worsening, or you think it may be an emergency, call your local emergency number or go to the nearest emergency department.
Bones & Joints
Mucous cysts (digital mucoid cysts) are small, fluid-filled bumps that develop on the finger (or rarely toe) near the fingernail, arising from the DIP (distal interphalangeal) joint—the joint closest to the fingertip—typically in people over 50 years with underlying finger arthritis. These cysts appear as translucent, dome-shaped lumps 3-10mm in size, filled with clear, jelly-like fluid (synovial fluid and mucin from the arthritic joint), and commonly cause nail deformity (groove running down nail if cyst presses on nail bed). While benign and not dangerous, they can be cosmetically bothersome or occasionally rupture and become infected. Treatment options range from observation (many patients tolerate them) to aspiration (temporary relief, 50-70% recurrence) to surgical excision with removal of underlying bone spur (90% cure rate but requires minor surgery under local anaesthetic).
What it is and why it happens
Mucous cysts (digital mucoid cysts) are small, fluid-filled bumps that develop on the finger (or rarely toe) near the fingernail, arising from the DIP (distal interphalangeal) joint—the joint closest to the fingertip—typically in people over 50 years with underlying finger arthritis. These cysts appear as translucent, dome-shaped lumps 3-10mm in size, filled with clear, jelly-like fluid (synovial fluid and mucin from the arthritic joint), and commonly cause nail deformity (groove running down nail if cyst presses on nail bed). While benign and not dangerous, they can be cosmetically bothersome or occasionally rupture and become infected. Treatment options range from observation (many patients tolerate them) to aspiration (temporary relief, 50-70% recurrence) to surgical excision with removal of underlying bone spur (90% cure rate but requires minor surgery under local anaesthetic).