Introduction The scientific literature has shown that the damage caused by sleep fragmentation in people affected by Obstructive Sleep Apnea (OSA) can reflect emotionally, generating not only physical symptoms such as drowsiness and tiredness, but also psychical symptoms, such as stress.

Objective This study aimed at comparing symptoms of stress in patients with moderate or severe OSA, before and after two months of treatment (clinical or surgical).

Method This isx an Individual, prospective, longitudinal, and interventional study. All patients underwent polysomnography before treatment. We collected data through the application of Stress Symptoms Inventory for Adults Lipp (ISSL) before and after two months of medical or surgical treatment for moderate or severe OSA.

Results The sample consisted of 18 patients (72.2% male) with a mean age of 51.83 years. We found that 77.8% (n = 14) of patients had stress in the first evaluation. In the second evaluation (after treatment), this reduced to 16.7% (n = 3). The average stress symptoms decreased from the first to the second evaluation (M = 13.78 and M = 6.17, respectively), being statistically significant (z = -3.53; p < 0.000).

Conclusions We found that moderate and severe apnea patients have significant stress index and that, after two months of medical or surgical treatment, there is a significant reduction of the symptom. In addition, the patients with severe OSA had a better outcome regarding the reduction of stress index than patients with moderate OSA.