Vocal cord nodule. Endoscope view of the larynx (voice box) of a patient, showing a nodule (small lump, centre) on the left vocal cord (lower right). A nodule is a harmless lump of tissue that forms on the vocal cords. It is caused by chronic (long-term) overuse of the cords whilst singing or speaking. If the vibration capacity of the cords is exceeded, too much friction is generated and a haematoma (an accumulation of clotted blood) is formed. The haematoma is later replaced with fibrous tissue, forming a nodule that causes hoarseness of the voice. Treatment involves complete resting of the voice and, in extreme cases, surgical removal of the nodule.