The term refers to the white dress shirts of male office workers common through most of the nineteenth and twentieth centuries in Western countries, as opposed to the blue overalls worn by many manual laborers.
The term "white collar" is credited to Upton Sinclair, an American writer, in relation to contemporary clerical, administrative, and management workers during the 1930s,[1] though references to white-collar work appear as early as 1935.
Less physical activity among white-collar workers has been thought to be a key factor in increased life-style related health conditions such as fatigue, obesity, diabetes, hypertension, cancer, and heart disease.
[2] Also, working at a computer could potentially lead to diseases associated with monotonous data entry such as carpal tunnel syndrome.
An example would be a restaurant manager who may wear more formal clothing yet still assist with cooking food or taking customers' orders, or a construction worker who also performs desk work.