{"id":3012,"date":"2024-02-10T18:35:04","date_gmt":"2024-02-10T18:35:04","guid":{"rendered":"https:\/\/integrativa.pt\/?p=3012"},"modified":"2026-01-29T16:56:29","modified_gmt":"2026-01-29T16:56:29","slug":"cortisol-melatonin-and-circadian-rhythm-understand-sleep-regulation","status":"publish","type":"post","link":"https:\/\/integrativa.pt\/en\/cortisol-melatonina-e-ritmo-circadiano-compreender-a-regulacao-do-sono\/","title":{"rendered":"Cortisol, melatonin and circadian rhythm: understanding sleep regulation"},"content":{"rendered":"
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The circadian cycle is an approximately 24-hour system of biological regulation responsible for organising multiple physiological processes, including sleep, wakefulness, metabolism and the response to the sun. stress.<\/em> Among its main modulators are cortisol and melatonin, two hormones with complementary functions in the body's adaptation to the different periods of the day and night.<\/p>\n

Cortisol, often referred to as the hormone of stress,<\/em> has a well-defined circadian pattern. Its levels tend to be highest in the early hours of the morning, contributing to an increase in alertness, energy mobilisation and the ability to respond to the demands of the day. Over the course of the day, cortisol levels progressively decrease, participating in the regulation of metabolism, the inflammatory response and the hydroelectrolytic balance, i.e. the proper regulation of water and mineral salts in the body.<\/p>\n

Melatonin, on the other hand, is associated with the transition to rest. Its production increases with a decrease in ambient light, especially at the end of the day, signalling to the body that the rest period is approaching. This hormone is involved in reducing core body temperature, decreasing muscle tone and facilitating the mechanisms that promote the induction and maintenance of sleep. Melatonin therefore plays a central role in the organisation of sleep and in the processes of physiological recovery during the night.<\/p>\n

The relationship between cortisol and melatonin can be understood as a dynamic system of alternation and balance, essential for an adequate transition between the states of wakefulness and rest. When this balance is preserved, the body tends to adapt more efficiently to daily rhythms. On the other hand, states of stress<\/em> chronic, persistent changes in routines or inadequate patterns of light exposure can interfere with this regulation, leading to sleep disturbances and changes in overall well-being.<\/p>\n\n\t\t<\/div>\n\t<\/div>\n\n\t

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\"Biorhythms\"<\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t
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Strategies that can support circadian balance and sleep quality<\/h4>\n

Some everyday behaviours can contribute to a more consistent organisation of the circadian rhythm:<\/p>\n