Headache (chronic daily)

• Chronic migraine
• Chronic tension-type headache
• New daily persistent headache
• Hemicrania continua

Chronic migraine

These headaches evolve from episodic migraine without aura. To be diagnosed with chronic migraine, you must have headaches — migraine, tension-type or both — 15 days or more a month, for at least three months. In addition, on eight or more days a month for at least three months, you must experience the following symptoms.

Your headaches have at least two of the following characteristics:

• Affect only one side of your head
• Cause a pulsating pain
• Cause moderate to severe pain
• Are aggravated by routine physical activity

And they cause at least one of the following:

• Nausea, vomiting or both
• Sensitivity to light and sound

Alternatively, if your headaches respond to triptan medications or ergot medications taken in anticipation of these symptoms — on eight or more days a month for at least three months — they're also considered chronic migraines.

Chronic tension-type headache

These headaches evolve from episodic tension-type headaches. They may last hours or be constant.

Chronic tension-type headaches have at least two of the following characteristics:

• Hurt on both sides of your head
• Cause mild to moderate pain
• Cause pain that feels pressing or tightening, but not pulsating
• Aren't aggravated by routine physical activity

In addition, they cause no more than one of the following:

• Sensitivity to light or sound
• Nausea (mild only)

New daily persistent headache

These headaches become constant within a few days of the moment you have your first headache.

New daily persistent headaches have at least two of the following characteristics:

• Hurt on both sides of your head
• Cause pain that feels like pressing or tightening, but not pulsating
• Cause mild to moderate pain
• Aren't aggravated by routine physical activity

In addition, they cause no more than one of the following:

• Sensitivity to light or sound
• Nausea (mild only)

Hemicrania continua

These headaches cause pain on only one side of your head that doesn't shift sides. They also:

• Are daily and continuous with no pain-free periods
• Cause moderate pain but with spikes of severe pain
• Respond to the prescription pain reliever indomethacin (Indocin)
• May sometimes become severe with development of migraine- like symptoms

In addition, hemicrania continua headaches cause at least one of the following:

• Tearing or redness of the eye on the affected side
• Nasal congestion or runny nose
• Drooping of the eyelid or constriction of the pupil

Causes

The causes of many chronic daily headaches aren't well understood. True (primary) chronic daily headaches don't have an identifiable underlying cause. They may occur if:

• You develop a heightened response to pain signals
• The part of your brain that suppresses pain signals isn't working properly

Other frequent headaches may be caused by various underlying diseases or conditions, including:

• Inflammation or other problems with the blood vessels in and around the brain, including stroke
• Infections, such as meningitis
• Intracranial pressure that's either too high or too low
• Brain tumor
• Traumatic brain injury

Many people who have frequent headaches are actually experiencing a rebound effect from taking pain medication too often. If you're taking pain medications — even over-the-counter analgesics — more than three days a week, you're at risk of developing rebound headaches.

Risk factors

Various factors may increase the risk of developing frequent headaches, including:

• Anxiety
• Depression
• Sleep disturbances
• Obesity
• Snoring
• Overuse of caffeine
• Overuse of pain medication
• Regular use of physical postures that put a strain on your head or neck

Complications

If you have chronic daily headaches, you're also more likely to experience depression, anxiety, sleep disturbances, and other psychological and physical problems.

Diagnosis

Your doctor will probably do a physical exam to check for signs of illness, infection or neurological problems. If the cause of your headaches remains uncertain, you may need blood or urine tests to identify any underlying medical conditions. Sometimes imaging studies — such as an X-ray, CT scan or MRI scan — are recommended.

References:

http://www.americanheadachesociety.org/assets/1/7/NAP_for_Web_-_CDH___Chronic_Migraine.pdf

http://patient.info/health/chronic-tension-type-headache

http://www.neurology.org/content/76/7_Supplement_2/S37.full

https://www.migrainetrust.org/about-migraine/types-of-migraine/chronic-migraine/

http://www.hopkinsmedicine.org/healthlibrary/conditions/adult/nervous_system_disorders/Chronic_Daily_Headache_22,ChronicDailyHeadache/

http://www.achenet.org/news/chronic_daily_headache/