This study evaluates the quality of sleep of patients admitted to medical and intensive care units. All of them will have a clock placed to measure their circadian activity. Also, data will be recorded through questionnaires about the unit, patient habits and medical problems.

The investigators found an extensive bibliography related to the quality of sleep and its effects on health. However, it should be noted the literary emptiness in relation to the influential factors in it. Chronobiology is the science responsible for studying the rhythmic changes in living beings; where the investigators include the circadian rhythm. In this way, all the "cycles" will be influenced by a series of factors that allow its correct operation, being in this case the light-dark cycle (LD), together with the temperature compensation, these being the determinants that allow, or not homeostasis.

The sleep - wake pattern is one of the most important circadian rhythms that happen in the organism. The dream is an unconscious process by which, despite the muscular relaxation that occurs, it is accompanied by continuous brain activity along with sensitive perception, where several of the organ systems come into play. This cycle is composed of two factors: a homeostatic one directly proportional to the time we are awake, and another circadian, dependent on the secretion of melatonin and the body's regulation of temperature. This fact can be compromised by the appearance of both external and internal stimuli, altering normal functioning, which is translated into sleep deprivation, which, if extended over time, can have physical and mental consequences, Some of them are: deterioration of the immune function, an increase in the incidence of cardiovascular diseases, memory deficit, early aging, mood swings, difficulty in healing, greater probability of developing metabolic syndromes, cognitive, affective disorders and even some types of cancer

The results obtained will facilitate the elaboration of action protocols focused on improving sleep quality in hospitalized patients.

Inclusion Criteria:

• subjects over 18 years of age, minimum duration of the hospitalization process of 96h, conscious and oriented with constancy in their clinical history (HC) and who give their consent.

Exclusion Criteria:

• personas con discapacidad visual y/o auditiva documentada en su HC, en el caso de los pacientes de Unidades de Cuidados Intensivos (UCIs) se excluirán a aquellos que obtengan una puntuación inferior a 8 en la escala Glasgow. Pacientes con cualquier tipo de aislamiento y aquellos incluidos en el plan de Cuidados Paliativos.

Users who are part of the study must be adults admitted to intensive care units (ICUs), Medical Units (UMs) and Surgical units (UQs), of the 13 participating hospitals: Andalusia (H. Juan Ramón Jiménez, Huelva), Catalonia (H. Mataró and H. Arnau Villanova, Lleida), Cantabria (HU Marqués Valdecilla), Castilla y León (H. del Bierzo, Ponferrada), Castila-La Mancha (HGU Ciudad Real), C. Madrid (HU 12 de Octubre ), C. Valenciana (HGU Valencia and HGU Alicante), Murcia Region (C H Cartagena, HCU V Arrixaca) and Basque Country (H. Basurto, Bilbao and H. Galdakao-Usansolo, Vizcaya).