Can you tell the time based on your headache?

According to a new study published in Neurology on Wednesday, migraines and cluster headaches are linked to the body’s internal clock.

The study found that both types of headaches have strong connections to the circadian system, which is responsible for the physical, mental, and behavioral patterns that follow a 24-hour cycle.

Migraines are a type of headache that can recur and range from moderate to debilitating pain, lasting anywhere from four to 72 hours. They affect women three times more often than men, according to the National Institutes of Health.

Cluster headaches are the most common type of primary headache and are three times more likely to be experienced by men, the NIH reports. They often come with nasal congestion and are short-lasting, with episodes occurring from every other day to as often as eight times a day.

Many vital bodily functions, such as sleep cycles, hormonal activity, body temperature rhythm, eating and digestion, are regulated by an individual’s circadian clock.

According to a new meta-analysis, which analyzed previous research, the timing of headaches, as well as the genes and hormones linked to the circadian clock, were studied. The analysis found that 71% of 4,953 participants across 16 studies showed a significant circadian pattern of cluster headaches.

The link between migraines and circadian rhythms was weaker, at 50%, compared to cluster headaches, but the study still found that migraines were affected by the body’s internal clock in some aspects.

Migraine attacks occurred less frequently at night compared to cluster headaches.

Two primary circadian genes were also associated with migraines, and 110 out of 168 genes showed a pattern of circadian expression.

Individuals who suffered from migraines were found to have lower levels of melatonin in their urine compared to those who didn’t, and these levels decreased even further during a migraine attack.

“The data suggest that both of these headache disorders are highly circadian at multiple levels, especially cluster headache,” explained study author Mark Joseph Burish, M.D., Ph.D., of the University of Texas Health Science Center in Houston and a member of the American Academy of Neurology.

“This reinforces the importance of the hypothalamus — the area of the brain that houses the primary biological clock — and its role in cluster headache and migraine. It also raises the question of the genetics of triggers such as sleep changes that are known triggers for migraine and are cues for the body’s circadian rhythm.”

Experts note that this research suggests that circadian-based treatments — such as taking medications at certain times of the day — should be explored for headache disorders.

According to the Centers for Disease Control and Prevention (CDC), adults should get a minimum of seven hours of sleep each night.

However, it seems that many Americans are not meeting this recommendation, and even if they are, their sleep is often inconsistent.

Almost half of all American adults suffer from sleep deprivation, citing a discrepancy between their biological and social clocks.

Being out of sync with the circadian rhythm has been linked to an increased risk of various health problems, including depression, obesity, Type 2 diabetes, cardiovascular diseases, and now, headache disorders.