Circadian rhythm: when your body clock is out of time.

A problem of schedule, not quantity

The circadian rhythm is the 24-hour cycle that regulates sleep, wakefulness, temperature and many body functions. It adjusts every day thanks to external signals, especially thelight. When the internal clock goes forward, slow, or loses stability, the person sleeps.at the wrong time: You can sleep well, but at the wrong time.

The typical thing is not being able to sleep until very late and having a hard time getting up (phase delay), or on the contrary, falling exhausted early and waking up at dawn (phase advance). Shift work and travel with jet lag also throw off the clock.

The consequence is fatigue, poor performance and conflict with school or work schedules. The key to treatment is not “sleeping more,” butreset the clock.

Circadian rhythms and sleep

Sleep, like other functions of the body (hormones, metabolism, etc.), is regulated by the so-calledbiological clock: a neuronal center located in the cerebral hypothalamus whose function is to give the signal to the rest of the brain to start and end sleep. In this way, the clock establishes at what time the propensity to sleep increases and at what time it decreases.

When activated, the biological clock sends a signal to the pineal gland to begin production ofmelatonin, the hormone that coordinates the body adapting so that sleep can begin.

Under normal conditions, the clock is synchronized with external luminosity through the retina. Thus, as the day ends and the light decreases, drowsiness appears a few hours later. However, exposure toartificial light typical of the modern worldand, more recently, to televisions, computers, tablets and mobile phones at night, can delay the activation of the brain centers that regulate sleep for several hours.

Types of insomnia linked to a disrupted sleep–wake rhythm

Rhythm disorders manifest themselves in different ways. The common denominator is that the amount of sleep may be normal, but it occurs at the wrong time:

Phase delay syndrome.The person has difficulty falling asleep at the usual hours (for example, at 11 or 12 at night): at that time they are completely awake and sleep only comes hours later, well into the early morning. Once she falls asleep, she does so deeply. If you have to get up early, you sleep few hours, you feel tired and have poor performance in the morning. In mild cases it can manifest itself simply by sleeping 1 or1.5 hours lessthan it should; In more severe forms, falling asleep at 4 or 5 in the morning.

Phase advancement syndrome. it is the opposite situation: the cycle begins early (for example, at 8 in the afternoon) and also ends early, with waking up completely sleepless in the early morning. It is more common in older people and can occur in families with an associated gene.

Irregular sleep rhythm.Sleep is fragmented into episodes that never exceed several hours, randomly both at night and during the day. It occurs mainly in some neurological disorders; In its minor form, any chronic insomnia can end up having a certain irregular component.

Jet lag. it occurs when crossing suddenlythree or more time zones. Between the United States and Europe there are six or more hours of difference. The biological clock continues to mark the time of origin: a traveler who leaves Boston at 7 in the afternoon and lands in Madrid at 9 in the morning (local time) has the body functioning as if it were 3 in the morning. Adaptation occurs slowly, approximately1.5 hours per dayelapsed. It does not depend on the duration of the flight, but exclusively on the number of time zones crossed.

How do you know if insomnia is due to the brain clock?

Frequently, insomnia is not only due to poor stress management, but also to an abnormal functioning of the biological clock. If you can sleep well, but not at the time you want, you may have a sleep rhythm disorder. Some people sleep well between6 and 14, or between19 and 2in the morning, but they cannot sleep when they try to do so between 11 and 7 in the morning.

Signs that insomnia may mainly come from a disrupted sleep–wake rhythm:

• Difficulties initiating or maintaining sleep, especially at the beginning of the night, to a much lesser extent if you try at other times.
• The problem began in adolescence or even childhood.
• The problem occurs almost daily, regardless of the stress level or environment.
• It gets worse when crossing multiple time zones.
• Improves with the administration of melatonin.
• It is associated with daytime hypersomnolence: there is no difficulty sleeping at certain times of the day.
• There are family members affected by a similar problem.

Reset your internal clock

The treatment does not consist of taking sleeping pills, but ratherreeducate the clock. The main tools areluz(seek it or avoid it at the appropriate times, with phototherapy if appropriate),melatoninascheduled at the correct time - its effect depends a lot on the moment in which it is taken - and someschedule routinesstable.

We design a personalized plan according to your type of imbalance, your chronotype and your obligations (studies, work, shifts). In shift work and jet lag we also give specific strategies for light and naps. With consistency, most people manage to sleep at the time they need.