He was born 10 December 1982 in Mardin, Turkey holds the Guinness World Record for tallest living male at 2.51 m (8 ft 3 in).
His growth has resulted from a tumour affecting his pituitary gland. His stature is such that he must use crutches in order to walk.
Kösen lives with his parents, three brothers and sister, who are all of normal height. He was unable to complete his schooling because of his height and works part-time as a farmer.Despite his height he claims to enjoy a normal lifestyle and enjoys playing computer games with his friends. He describes the advantages of being tall as seeing a great distance and being able to help his family with domestic tasks such as changing light bulbs and hanging curtains. He lists disadvantages as not being able to find clothes (inside leg measuring 44.5 inches (113 cm) and sleeve length measuring 38 inches (97 cm)) or shoes (size 28) that fit or finding it extremely hard to fit into an average-sized car.
Starting in 2010, Kösen received Gamma Knife treatment for his pituitary tumour at the University of Virginia Medical School and has also been provided with medication to control his excessive levels of growth hormone. Although the full effect of the treatment takes up to two years, as of 2011, his hormone levels were almost normal. It was confirmed in March 2012 that the treatment had been effective in halting Kösen's growth.