fibrosis
Medical term for the formation of excess fibrous connective tissue in an organ or tissue.
Pulmonary fibrosis can cause breathing difficulties.
myelofibrosis
cystic fibrosis; mucoviscidosis
Common kanji spelling for fibrosis; 線維 means 'fibrous tissue'.
Alternate kanji spelling using 繊維 (fiber); both forms are used in medical contexts.
Compound of 線維 (sen'i, 'fiber') + 症 (shō, 'disease, condition').