The aim of this work was to assess the prevalence of palmar and axillary hyperhidrosis among young Polish adults. Additionally, this work aimed at comparing the subjective and objective (gravimetric) method of hyperhidrosis assessment. Healthy medical students, volunteering to take part in this study, were included. The participants filled out a questionnaire assessing the occurrence and subjective intensity of hyperhidrosis in different areas of the body. Additionally, the students were subjected to gravimetric assessment in four localizations: the face, palms, axillae and abdomino-lumbar area. Two hundred and fifty-three students (102 males and 151 females, mean age 24.3 ± 3.21 years) were included in the study. Forty-two (16.7%) participants declared that they suffer from hyperhidrosis. Out of the 42 students declaring any type of hyperhidrosis, only 20 (47.6%) exceeded the gravimetric reference values. From among the students that exceeded the normative values for palmar hyperhidrosis, only 10 (55.6%) were aware of their hyperhidrosis. In the group of students that exceeded the normative values for axillary hyperhidrosis, 16 (39%) were aware of their hyperhidrosis. Subjectively declared hyperhidrosis incidence may significantly exceed the real-life occurrence of this disease. Basing studies solely on data gathered from questionnaires, may lead to false results. It is imperative, when assessing patients suffering from hyperhidrosis, to use both objective and subjective methods of evaluation.