Headaches are extremely common, affecting two to four percent of the world’s population. The causes are complex, and waking up with a headache introduces new variables. More often than not, people ignore or fail to report morning headaches because getting on with the busy day is more important.

Nighttime Teeth Grinding

During sleep, some people grind their teeth, a condition called bruxism. With the help of polysomnography, researchers can firmly link sleep-related bruxism and waking up with a headache. One case showed that teeth-grinding resulted in problems with the individual’s temporomandibular joint, resulting in bilateral, pulsing morning headaches that went on for years.

Strained Neck Muscles

Poor sleep can lead to waking up with a stiff neck from prolonged, awkward sleeping positions. Below the skull are the suboccipital muscles, which can compress surrounding nerves if they become tense or inflamed. This results in tension headaches that make it feel like someone is slowly squeezing the head and eyes.

Hangover

The effects of alcohol intoxication on the excretory system are numerous. Too much ethanol, the primary component of alcohol, increases urination and leads to dehydration and the dreaded morning hangover headache. Alongside that process, the liver metabolizes alcohol into acetaldehyde, a known precursor of formaldehyde. This toxic by-product leads to many of the symptoms associated with hangovers.

Too Much Medication

Taking over-the-counter medications too often or in too high of dosage may cause rebound headaches. These feel different every time, as the pain tends to wander and is accompanied by other symptoms, such as nausea and bouts of insomnia. Ironically, people who take too much aspirin or sedatives for headaches may experience regular rebound headaches.

Caffeine Withdrawal

Caffeine is one of the most common alkaloids, found in numerous products, from beverages to medications. It is a powerful vasoconstrictor that reduces cerebral blood flow by close to 30 percent. Heavy users who abstain from caffeine can experience withdrawal headaches within 24 hours, as other chemicals in the body, namely the neurotransmitter adenosine, try to compensate for the loss. This results in dilated blood vessels, which causes headaches.

Low Blood Sugar

Low blood sugar or hypoglycemia is common in people with diabetes and can deprive the brain of a critical energy source: sugar. When blood sugar falls too quickly to or below 50 mg/dL, individuals experience dull throbbing at the temples as the brain tries to adjust to this lack of resources.

Sleep Apnea

More than 18 million Americans deal with some form of sleep apnea, with roughly two to three percent exhibiting the obstructive form. In a study of over 80 people with obstructive sleep apnea, results show that the intensity and duration of their morning headaches depend on the severity of their condition.

Hypertensive Crisis

For the most part, slight increases in blood pressure do not cause headaches. In approximately 20 percent of people, however, they can develop during hypertensive crisis. This event causes arterial blood pressure to quickly rise 180/120 mmHg or higher, resulting in general organ crisis. Specifically, the change in intracranial blood pressure induces headaches, and, if left untreated, can lead to a medical emergency.

Treatment

Treating morning headaches means addressing the underlying causes. For example, headaches triggered by low blood sugar can be reduced by eating smaller meals more regularly to maintain balance. People with obstructive apnea may need to wear a CPAP device nightly that keeps airways open at night. This increases sleep quality and reduces the chances of waking up with a headache.

Prevention

One common cause of headaches is poor sleep. In many cases, better sleep hygiene practices can help, such as less exposure to bright or blue-wave lighting right before bed, having a consistent bedtime, and creating an environment conducive to restful sleep. Some dietary techniques can help as well, include avoiding sugary or hard-to-digest foods a couple hours before sleep.