What Are Hypnic Headaches?

Causes of Hypnic Headaches

Currently, experts continue to research possible causes of hypnic headaches. At the moment, doctors agree these headaches should be classified as a primary headache disorder, meaning they are benign and not caused by underlying medical conditions such as brain tumors. Studies suggest there may be a link between hypnic headaches and certain stages of sleep, particularly rapid eye movement (REM) sleep. Additional research suggests patients with this condition could have functional issues in the regions of the brain responsible for pain control and melatonin production. For some patients, headaches may be triggered or exacerbated by environmental factors. Insufficient or excessive sleep, exposure to bright light, and stress are recognized triggers. In addition, hormonal changes, dehydration, and the use of certain medications might cause or worsen headaches too. To help the patient determine if any triggers may be exacerbating their hypnic headaches, a neurologist will take a thorough health history, asking about sleep patterns, stress levels, diet, and medication use.

Diagnosing The Headaches

The process of diagnosing the headaches is often lengthy, and it includes a battery of tests. To help the doctor in the diagnostic process, patients should let the healthcare team know about all medications they take as part of the health history. Several medications, including estrogen and nitroglycerin, can cause symptoms that mimic hypnic headaches. After completing the health history, the doctor will perform a complete physical exam to rule out other conditions that could be causing the headaches. This will include checking the patient's blood pressure and cardiovascular health. Occasionally, high blood pressure at night or reduced blood flow in the carotid arteries could cause headaches, and doctors will want to rule this out, possibly with an ultrasound of the carotid arteries.

The physician will also perform a neurological exam to check the patient's coordination, sensation, and muscle tone. After finishing the exam, the patient may be asked to have further tests such as blood tests and imaging studies. These tests can help detect brain tumors, stroke, infection, and internal bleeding that could be contributing to the patient's symptoms. For example, blood glucose testing is performed to check for low blood sugar, a potential cause of nocturnal headaches. Sometimes, patients may need to have sleep studies at home or in a sleep laboratory. These studies measure the patient's oxygen levels, breathing, and brain activity during sleep, and they can detect sleep apnea, one of the major causes of nighttime headaches.