Sleep disorders are extremely common in the population. There are no exact data on the prevalence of sleep disorders in Estonia. In Western Europe, according to a cross-sectional study among people older than 15 years, 31% of people have sleep disorders. Half of the people with sleep disorder complaints have not done anything to relieve them, nor have they consulted a doctor (1). Sleep disorders are thus an underdiagnosed clinical problem. Undiagnosed and untreated chronic sleep disorders increase the risk of hypertension, diabetes, myocardial infarction and cerebral infarction, as well as the risk of traffic and occupational accidents. Sleep disorders negatively affect work productivity as well as social and family relationships (2). AASM estimates (3) that timely diagnosis and treatment of sleep apnea alone would save the health care system billions of dollars annually. Sleep medicine is a multidisciplinary field. Sleep disorders often co-occur with psychiatric, cardiovascular, neurological, pulmonological and otorhinolaryngological diseases. Doctors of various specialties and representatives of medicine-related specialties come into contact with patients with sleep disorders on a daily basis. By diagnosing sleep disorders in a timely and correct manner, appropriate interventions can be implemented, the aim of which is to improve the patient's quality of life and work and traffic safety, and reduce healthcare costs. The Estonian Sleep Medicine Society was founded in 2005. From the beginning, the society's goals have been to educate the medical profession, the public, and legislators in the field of diagnosis and treatment of sleep disorders. Evidence-based diagnostic guidelines for sleep disorders have not been prepared for primary health care workers in Estonia before, this guide is the first. Several specialized sleep centers operate in Estonia, where complex diagnostics and treatment of sleep disorders are carried out. For health care organizational reasons, in many cases the cost of sleep studies is borne by the patient. However, a more comprehensive differential diagnosis of sleep disorders is usually beyond the competence and capability of primary care medicine. This guide provides recommendations for the diagnosis of sleep disorders in primary care with accessible and feasible methods that almost do not involve instrumental diagnostics. Sleep disorders are mostly indicated by subjective sleep complaints. Diagnosis of sleep disorders at primary level therefore involves the use of several evidence-based questionnaires. This guide does not cover the prevention or treatment of sleep disorders. The algorithms contain recommendations for each sleep disorder, in which case the patient should be referred to a specialist dealing with sleep disorders (see Appendix 1). Sleep disorders are overlooked because of nonspecific daytime (eg, fatigue, cognitive difficulties) and nighttime (eg, snoring) symptoms. Also, sleep disorders are often overshadowed by accompanying psychiatric and physical illnesses.