Atypical thyroid tests in an athlete treated for hypothyroidism as the first symptom of pituitary dysfunction due to relative energy deficiency

Atypical thyroid function tests in athletes may be the first manifestation of reversible pituitary dysfunction due to relative energy deficiency. Typical symptoms of relative energy deficiency include reversible suppression of the hypothalamic-pituitary-thyroidal axis and hypothalamic-pituitary-gonadal axis. Relative energy deficiency may occur in all people who train intensively, regardless of their body weight and BMI, as well as in people who have rapidly lost weight as a result of a low-calorie diet and intense exercise.