A method for evaluating a health condition, includes: measuring a test amount of cell free DNA per unit amount of a body fluid sample collected from a subject after tumor resection; and comparing the measured test amount of cell free DNA with a reference value so as to evaluate a health condition of the subject. The reference value is one of a predetermined threshold value; an amount of cell free DNA per unit amount of a body fluid sample collected from the subject before tumor resection; an amount of cell free DNA per unit amount of a body fluid sample collected from the subject between 1 week and 3 months after tumor resection; and an amount of cell free DNA per unit amount of a body fluid sample collected from the subject by the time of collecting the body fluid sample for measuring the test amount of cell free DNA.