Frequent headaches are not a normal occurrence and can be an indication of an underlying problem. 

Headaches can be caused by a variety of issues ranging from tension to obstructive sleep apnea.  Here we will address the types of headaches and causes.

It is important to realize that headaches have many different causes and a wide range of severity.  Immediate medical help should be sought for any head pain that leads to any of the following:  Weakness of an arm or leg, loss of vision, disorientation, or loss of consciousness.

Headache specialists generally divide headaches into two groups: primary and secondary.  

Primary headaches are far more common than secondary headaches. By definition, these headaches are “idiopathic” — occurring for no obvious reason; not the result of any other underlying disease or process. It will likely turn out that these conditions have a complex interplay of genetic, developmental, and environmental risk factors.

Common primary headaches include migrainetension-type, and cluster. Because these headaches by definition are not being caused by any underlying problem, neurological examinations and imaging tests usually yield completely normal results, no matter how severe the symptoms.  Thus there are no tests for these headaches, only tests to rule out other causes. Increasingly, we think of these headaches as a result of a problem with brain function rather than brain structure. While painful or even disabling, primary headaches are almost never dangerous in and of themselves.

Secondary headaches are the ones that are more worrisome. They may be the result of serious underlying diseases or other conditions, ranging from brain tumors, to aneurysms, inflammatory diseases, or abnormalities of the spinal fluid. While these types of headaches are relatively rare, it is important to recognize them because the underlying disease causing the headaches may require urgent diagnosis and treatment. Even if the underlying disease is not particularly threatening, secondary headaches generally will not resolve until the specific cause is diagnosed and addressed.

Each patient’s headaches require careful diagnostic assessment to determine whether or not there is an underlying cause.  

These headaches will not be covered here and should you suspect you are experiencing a secondary headache, you should consult your medical doctor immediately.

(Thank you to Johns Hopkins Headache Center for the above information.)


Tension Headaches

Tension headaches are the most common of all headaches, found in all age groups and are nearly equal in prevalence among men and women, they typically are expressed with pain in the front of the head and base 
of skull, as seen in figure 1.  Tension type headaches typically have pain that radiates in a band like fashion on both sides, from forehead to base of skull. Pain often starts or radiates to the neck and upper back (trapezius) muscles.


The term migraine is originally derived from the Greek word hemicrania, which means "half of the head." And, for 70 percent of the time, the migraine is one-sided or occurring on one side of the head (figure 7). A migraine is considered a vascular headache because it is associated with changes in the size of the arteries in and outside of the brain. These vascular changes are ultimately caused by the Trigeminal Nerve/Ganglion.  An inflammation, or recurring antagonistic signals to the Trigeminal Nerve/Ganglion in your head trigger a chain reaction: the changes in serotonin in the blood vessels and the brain lead to shifts of blood flow, bypassing the capillaries and going through shunts to the veins.

The distention of these vessels contributes to the pain of migraine. The nerves around the blood vessels release chemicals, which cause inflammation eliciting pain signals into the brain/head. The Trigeminal Nerve/Ganglion receives its information from the jaw, mouth, face, teeth (figure 8), and all over the body (through the subnucleus caudalis).  If nociceptive (pain) signals to the Trigeminal Ganglion can be significantly reduced or eliminated, the result seen is a reduction or elimination of Migraines.  What's most important however, is obtaining an accurate diagnosis - which may indicate the need for multidisciplinary care.

Migraine headaches typically last from 4-72 hours and vary in frequency from daily, to fewer than 1 per year. Migraine affects about 15% + of the population. Three times as many women as men have migraines.


Cluster Headaches

Cluster Headaches are characterized by severe, unilateral pain that is around the eye or along the side of the head (figure 9); these are seen 5-8 times more commonly in men that women.  Cluster Headache attacks last from 5 to 180 minutes, and they can occur once every other day to up to 8 times daily. 

Attacks are associated with tearing on the same side of the head that the pain is located. Patients may also experience nasal congestion, runny nose, forehead and facial sweating, dropping eyelids or eyelid swelling.

Most people get their first cluster headache at age 25 years, although they may experience their first attacks anytime from their teens to early 50's - when they typically will begin to automatically reduce.

There are 2 types of cluster headache:

  1. Episodic: This type is more common. There may be 2 or 3 headaches a day for about 2 months, and then not another headache for a year. The pattern then will repeat itself.
  2. Chronic: The chronic type behaves similarly but it occurs chronically.

Cluster headaches have been strongly correlated with obstructive sleep apnea. Typically CH occurs between 9pm and 9am, and is worse during REM sleep, where sleep apnea is at its worst.


Facial Pain, Cranial Neuralgias and Other Headaches

Facial Pain, commonly called atypical facial pain, was first introduced by Frazier and Russell in 1924. It has since been renamed Persistent Idiopathic Facial Pain (PIFP). PIFP refers to pain along the territory of the trigeminal nerve (figure 10A and 10B) that does not fit the classic presentation of other cranial neuralgias (Pascual, 2001). The duration of pain is usually long, lasting most of the day (if not continuous). Pain is usually confined at onset to a limited area on one side of the face, has a deep ache, and is poorly localized. PIFP affects both sexes roughly equally, but more women than men have seeked medical care.


Cranial Neuralgias

The causes of Neuralgias are many, starting most commonly with compression, irritation or a distortion of cranial nerves or upper cervical roots by a structural distortion.  Other possible causes are herpes infection, diabetic neuropathy, Tolosa-Hunt Syndrome (a painful ophthalmoplegia caused by nonspecific inflammation of the cavernous sinus or superior orbital fissure), or they may have a Central Origin, meaning from the Central Nervous System, which implies it can be 'referred' or 'sensitized' pain from the TMJ.

Other Headaches

One of the possible causes of other headaches is a Sleep Disordered Breathing issue such as Obstructive Sleep Apnea, causing a hypoxia, or decreased level of oxygen. The low level of oxygen eventually changes the vasculature inside the brain, leading to headaches.

Sinus Headaches (figure 13) can be caused by inflammation in the mucosal linings of the frontal, maxillary, or ethmoid sinuses or the nasal cavity itself.  The inflammation is typically due to a viral, bacterial, or fungal infection or allergies. Healthy sinuses allow mucus to drain and air to circulate throughout the nasal passages. When sinuses become inflamed, these areas get blocked and mucus cannot drain. When sinuses become blocked, they provide a place for bacteria, viruses, and fungus to live and grow rapidly. Although a cold is most often the culprit, a sinusitis can be caused by anything that prevents the sinuses from draining. 

However, sinus headaches¬Ě have been found in people without any sinus or nasal congestion whatsoever.  This is typically due to a referral of pain from an unknown source, typically seen in our office from referred jaw pain. Pain often originates from an area that's not where the pain is felt; this is called referred pain.  As seen in figure 14, there can be facial, eye and top of the head pain referred from the SCM (sterno-cleido mastoid muscle).  Or even jaw and side of head pain referred from the Trapezius muscle (Figure 15). As mentioned at the beginning of this page, an accurate diagnosis is the key in getting resolution.


(Thank you Google Images for many of the above images)