When most of us have a headache, it is likely that we are experiencing a tension-type headache—a dull, mild-to-moderate pain that wraps around the entire head as if being squeezed by a vice grip. In fact, tension headaches are the most common manifestation of head-related pain, so much so that it is often nicknamed ‘ordinary headaches.’
While most of these come and go without causing a significant disruption, tension-type headache can still resemble a persistent disorder for a small percentage. It can develop anew after a head injury, it can move from infrequent to chronic, and it can even feature other symptoms such as those commonly associated with migraine.1 One of those symptoms is light sensitivity, which can regularly affect those with these types of headaches.
Light Sensitivity in Tension-Type Headache
The diagnostic indicators of tension-type headache (TTH), whether episodic or chronic, include sensory symptoms like light sensitivity, also called photophobia. However, whereas it is practically a prerequisite for migraine, it may or may not appear for TTH. In fact, light or sound sensitivity can be reported by patients, but both cannot occur together—otherwise doctors should be exploring alternative diagnoses. Other studies reinforce that photophobia pain scores are lower and threshold levels for bright light are higher when compared with other headache variations.2,3
Yet we know this sensitivity still happens regularly for those with tension-type headache. In fact, nearly 90% of patients self reported light intolerance during the headache phase, which puts it on par with migraine and other headache disorders. Other examinations have put the percentage closer to one in four who deal with photophobia, which probably more accurately reflects the broader TTH population.4,5
Light sensitivity can develop at any stage of this headache process too just as it can with the migrainous attack. About half of those with TTH have this hypersensitivity prior to the headache-related pain, occurring in what many call the ‘prodrome’ or pre-attack stage (although some experts believe that no such stage exists for tension-type headache). Even after the attack when the pain has mostly dissipated, more than two-thirds believed light still caused or worsened pain. And very little difference was noted for episodic or chronic tension-type headache, meaning photophobia is likely to affect them equally.4,8
Migraine and tension headache are not mutually exclusive either. Patients can have “coexisting” disorders with chronic—even daily—tension-type headaches and regular migraine attacks. As a result, this can enhance the likelihood that sensitivity to light becomes a feature of the headache stage. Clearly, these numbers prove that photophobia is a persistent problem for those with the condition.
Light Triggers in Tension-Type Headache
Similarly with migraine and other headache disorders, tension headaches can have triggers that precede and likely initiate the attack. Many resemble those that are reported among migraineurs, but they often trigger less reliably in TTH. This makes their identification not particularly useful for diagnosis BUT absolutely helpful in management or treatment of the headache condition. Some of these common aggravating factors include:
- Lack of sleep
- Skipping meals
- Caffeine withdrawal
- Environmental factors
Among environmental factors, bright lighting can be a prominent catalyst for these headaches. Generally, less than half of TTH patients cite exposure to light as an instigator for their pain, and those with both migraine and tension headache are generally more affected by visual stimuli.6 That said, sunlight in particular can bring on headache pain in nearly 30% of patients, behind only stress. And once again, those with a migraine disorder have a greater risk of having sunlight sensitivity.7
Another way that light can trigger a tension-type headache episode centers around the secondary physical consequences of light exposure. For example, our extensive use of devices with digital screens can lead to eye strain and fatigue. The lack of eye and head movement coupled with the screen intensity and blue light wavelengths can cause the eyes to dry up, facial muscles to tighten and ultimately bring about tension headaches. Given the lower tolerance for light that people with TTH have, the screen light is likely to play a role in this process. This is why many of us feel like staring at our smartphone screen has given us headache pain at one time or another.
1Chowdhury D. Tension type headache. Ann Indian Acad Neurol. 2012;15(Suppl 1):S83–S88. doi:10.4103/0972-2327.100023
2Anagnostou E, Vikelis M, Tzavellas E, Ghika A, Kouzi I, Evdokimidis I, Kararizou E. Photophobia in primary headaches, in essential blepharospasm and in major depression. Int J Neurosci. 2017 Aug;127(8):673-679. doi: 10.1080/00207454.2016.1231185. Epub 2016 Sep 13.
3Wu Y, Hallett M. Photophobia in neurologic disorders. Transl Neurodegener. 2017;6:26. Published 2017 Sep 20. doi:10.1186/s40035-017-0095-3
4Vingen JV, Stovner L. (1998). Photophobia and Phonophobia in Tension-Type and Cervicogenic Headache. Cephalalgia. 1998;18(6):313–318.
5Ashina S, Lyngberg A, Jensen R. Headache characteristics and chronification of migraine and tension-type headache: A population-based study.Cephalalgia. 2010 Aug;30(8):943-52. doi: 10.1177/0333102409357958. Epub 2010 Mar 17.
6Wöber C, Wöber-Bingöl C. Triggers of migraine and tension-type headache. Handb Clin Neurol. 2010;97:161-72. doi: 10.1016/S0072-9752(10)97012-7.
7Haque B, Rahman KM, Hoque A, et al. Precipitating and relieving factors of migraine versus tension type headache. BMC Neurol. 2012;12:82. Published 2012 Aug 25. doi:10.1186/1471-2377-12-82
8Karli N , Zarifoglu M, Calisir N, Akgoz S .Comparison of pre-headache phases and trigger factors of migraine and episodic tension-type headache: do they share similar clinical pathophysiology? Cephalalgia. 2005 Jun;25(6):444-51.