Presenteeism: The problem of workers being on the job but, because of medical conditions, not fully functioning. The health problems that result in presenteeism include such chronic or episodic ailments as seasonal include: depression, back pain, arthritis, heart disease, high blood pressure, and gastrointestinal disorders. An example of presenteeism might ibe an employee who suffers from depression and so is less able to work effectively. And another example might be the employee with a migraine headache who may have difficulty looking at a computer screen.
In a sense, presenteeism is the opposite of absenteeism, in which the employee does not come to work. The term "presenteeism" was coined by Professor Cary Cooper, a psychologist specializing in organisational management at Manchester University in the UK.