There is limited information on changes over time in the incidence, age, sex, and comorbidities of obstructive sleep apnoea. We extracted data from the Finnish Secondary Care Register to assess the incidence of obstructive sleep apnoea, the age and sex distribution, and the prevalence of 26 comorbidities of incident obstructive sleep apnoea patients in Finnish specialized care in 2010 and 2020. Analyses were conducted for three age groups (18 − 39, 40 − 64, and ≥65 years), stratified by sex, and for the total population. From 2010 to 2020, the incidence of clinically diagnosed obstructive sleep apnoea increased from 1.7 to 6.1 per 1000 (from 2.4 to 7.6 per 1000 for men and from 1.0 to 4.6 per 1000 for women). The proportion of the youngest group increased from 11.0% to 12.7% and the oldest group from 20.2% to 27.2%. The largest increase in incidence was observed in the youngest group for both sexes. Among men, the prevalence of six comorbidities decreased, and of eight increased. Among women, the prevalence of seven comorbidities decreased, and of four increased. Obstructive sleep apnoea is being diagnosed increasingly in young adults and those aged 65 years and older. Changes in comorbidities suggest increased recognition and treatment of cardiovascular risk factors and, on the other hand, the ageing of the population. A decrease in some comorbidities suggests that incident obstructive sleep apnoea patients are less morbid despite their increased age.