For most patients, the cause of their carpal tunnel syndrome is unknown. Any condition that exerts pressure on the median nerve at the wrist can cause carpal tunnel syndrome. Common conditions that can lead to carpal tunnel syndrome include obesity, pregnancy, hypothyroidism, arthritis, diabetes, and trauma. Tendon inflammation resulting from repetitive work, such as uninterrupted typing, can also cause carpal tunnel symptoms. Carpal tunnel syndrome from repetitive maneuvers has been referred to as one of the repetitive stress injuries, although this relationship remains controversial in the evidence based literature. Some rare diseases can cause deposition of abnormal substances in and around the carpal tunnel, leading to nerve irritation. These diseases include amyloidosis, sarcoidosis, multiple myeloma, and leukemia.