A 2001 study of 4,315 Japanese patients at Ram Hospital in Chiang Mai found that the most common health complaints (classified according to ICD-10 coding) involved respiratory diseases (739 cases), digestive tract diseases, and infectious diseases.
A 2005 study of Japanese patients at Bangkok Hospital (11,200 patients, about one-eight of all non-Thai patients at the hospital that year) found that most patients were men in their 30s, 40s, and 50s; women and patients in their 20s were notably fewer [REF].