Chronic daily headache

What is chronic daily headache?

A useful definition of chronic daily headache (CDH) is when you have a headache for more than four hours on more than 15 days per month. Some people experience these headaches for a period of six months or longer.

Causes of chronic daily headache

Chronic daily headache is associated with:

  • head injury
  • a previous history of migraine
  • overuse of painkilling medications (see medication-overuse headache)
  • obesity
  • stressful life events
  • being female.


Caffeine, snoring and chronic daily headache

The below article is taken from Migraine News journal, Issue 88, Spring 2005.

As part of our commitment to fund and disseminate research, The Migraine Trust agreed to part fund Dr Ann Scher to carry out a ‘Case-Control Study of Chronic Daily Headache in the General Population’.

Dr Scher’s study examined the factors present when people with episodic headache develop chronic daily headache (CDH). The aim was to increase our understanding of the factors related to CDH and prognosis in the general population and discover whether some of the risk factors could be modified to reduce the chance of developing CDH. The study was carried out in America but is likely to have relevance elsewhere.

Chronic daily headache (CDH) affects 4% of the adult population. CDH is a term given to headaches that occur 15 or more days a month.

The type of headache pain can change depending on the individual’s situation and can consist of a number of different types of head pain. Research has shown that few sufferers with chronic daily headache seek medical care, and even fewer consult headache specialists. Therefore, it is important to study risk factors for chronic headache in population-based samples.

The factors the study looked at included:stressful life events, treatment patterns for headache, sleep disturbances, caffeine consumption and co-existing depression.

Here the focus is on the findings that are related to prognostic factors, medicinal and dietary caffeine consumption and habitual snoring.

Methods of the study

From a large sample of adults in the U.S. who had participated in a general health survey the study identified two groups of adults:

  • those with chronic daily headache (defined as 180+headache days per year)
  • a comparison group with episodic headache (defined as 2-104 headache days per year).

These individuals were contacted approximately one year after the health survey and interviewed again about their headaches and other factors.

The study identified:

  • individuals with a good prognosis – fewer headaches at the second interview.
  • individuals with a poor prognosis – more headaches at the second interview

The study then considered what factors, if any, were conducive to a better or worse prognosis at follow-up.

Caffeine and medication

Participants were interviewed about their current and past (pre-CDH) dietary caffeine consumption. The researchers calculated total caffeine consumption based on their typical consumption of coffee, caffeinated tea, caffeinated soft drinks and chocolate.

The study asked the participants about the medications that they normally used to treat their headaches and noted which participants used medication that contained caffeine. For this analysis the researchers defined high caffeine consumption as either:

a) using a caffeine-containing medication as their first choice headache treatment

or b) being in the top 25% of individuals in terms of dietary caffeine consumption.


Compared to the episodic headache group, at risk groups for CDH were those: of white European extraction; of female gender who have spent less time in education; who are divorced, widowed or separated who have a higher body mass index (risk of obesity) or with co-existing diabetes or arthritis. At the one-year follow-up-interview, 57% of the CDH sufferers reported that their headaches had reduced to fewer than 180 headache days per year. 14% reported that their headaches had reduced to fewer than one headache per week. The following groups had a better prognosis: African American groups and people from other non white groups; people who were married; people with higher educational attainment, and those diagnosed with diabetes.



CDH sufferers were almost three times as likely to be habitual (every day) snorers than the episodic headache comparison group. This did not appear to be due to the usual factors associated with snoring/sleep apnea (e.g. Male gender, increased age, weight, high blood pressure, alcohol consumption) nor did it appear to be due

to other headache-related factors that can affect sleep (e.g use of sedating pain medication, coexisting depression, caffeine consumption). The finding that CDH sufferers were more likely to snore was evident for both chronic migraine and chronic tension-type headache sufferers.


The CDH sufferers were more likely to have been high caffeine consumers than those in the comparison group before CDH onset, although the association was modest. There was no difference in current caffeine consumption between the episodic and chronic headache sufferers. High caffeine consumption appeared more important as a risk factor in some sub-groups of CDH sufferers, in particular:

  • women under 40
  • CDH sufferers with daily episodic (as opposed to daily continuous) headache
  • CDH sufferers who had not consulted physicians
  • those whose CDH started less than 2 years ago The migraine sufferers, whether episodic or chronic, consumed more medicinal or dietary caffeine than the other headache sufferers.


In this general selection of the US population, habitual snoring was surprisingly common amongst CDH sufferers, and appeared independent of the usual cardiovascular risk factors associated with sleep-disordered breathing. However, whether correction of snoring might improve headaches is currently unknown. Dietary and medicinal caffeine consumption was a modest risk factor for CDH onset overall. However, caffeine consumption might be more of a factor for some sub-groups (younger women, those with relatively recent onset of CDH, and those who had not consulted doctors about their headaches).


  1. Scher AI, A case-control study of chronic daily headache in the general population. PhD Dissertation, The Johns Hopkins University, 2001.
  2. Scher AI, Stewart WF, Lipton RB, Caffeine as a risk factor for chronic daily headache: A population-based study, Neurology, 2004;63: 2022-2027
  3. Scher AI, Stewart WF, Ricci JA, Lipton RB, Factors associated with the onset and remission of chronic daily headache in a population-based study, Pain 2003; 106/1-2:81-89.
  4. Scher AI, Lipton RB, Stewart WF, Habitual snoring as a risk factor for chronic daily headache, Neurology 2003;60:1366-1368.