Objective:
The aim of the study was assessment of health behaviours, degree of acceptance of the disease, and nutritional habits among patients with hypothyroidism and Hashimoto’s autoimmune thyroiditis.

Materials and method:
The study included 180 patients, conducted by the method of a diagnostic survey using the following instruments: the Questionnaire of Eating Behaviours (QEB), Health Behaviour Inventory (IZZ), and the Acceptance of Illness Scale (AIS).

Results:
The examined group was characterized by a mediocre intensity of health behaviours and obtained, on average, 82.87 scores per 118 possible scores. According to the Acceptance of Illness Scale, the respondents obtained 29.49 scores per 40, which evidences a relatively high acceptance of own medical condition. The higher the quality of the respondents’ diet, the higher the health behaviour index, whereas the level of nutritional knowledge had no effect on the pro-health and anti-health eating index.

Conclusions:
1. In patients with hypothyroidism and Hashimoto’s autoimmune thyroiditis the undertaking of health behaviours increased with age, most strongly in the domain of health practices and positive psychological attitude. 2. The intensity of health behaviours increased with the level of acceptance of the disease, especially with respect to positive psychological attitude. 3. Patients whose eating habits were characterized by a high quality of diet index (pro-health eating index), showed intensified health behaviours. The level of nutritional knowledge among patients with hypothyroidism and Hashimoto’s autoimmune thyroiditis was related neither with a high nor a low quality of diet index (pro-health and anti-health diet index).