The group of disorders known as chronic daily headache (CDH) afflicts 4-6% of the worldwide population and is a source of major disability in the form of lost or decreased functioning capability at home and work.
Chronic daily headache (CDH) refers to the unhappy situation in which headaches happen at least 15 days a month. They are more of a category than a final diagnosis, and different, recognizable patterns of headaches are included in this category. It’s important to distinguish between the different patterns because, once recognized, they can indicate the underlying cause and dictate appropriate treatment.
Primary And Secondary Headaches
CDH can occur in the form of primary headaches, or secondary headaches. Primary headache simply means that the headache itself is the disease (so, it’s not a symptom of something else), while secondary headache means that the headache is a symptom of another disease or process and in such a case the best treatment is the one that addresses the underlying cause of that particular disease or process.
The most common type of primary headache is tension headache. Generally, these headaches affect the left and right sides of your head, but sometimes they also affect the back of the head, your neck, and occasionally the front of your head, too.
These headaches are usually mild to moderate in intensity and have pressing or tightening qualities. Nausea, photosensitivity and sound sensitivity are not that prominent in this type of headache and they also do not worsen with exertion.
Migraine is another common type of primary headache and can be categorized as CDH when it happens more often than usual (which can usually last up to 72 hours if left untreated).
This type of headache is of moderate to severe intensity and it often has a pulsating characteristic attached to it. The migraine usually affects only one side of the head and can cause nausea, light sensitivity and sound sensitivity. This type of headache usually worsen with exertion.
Other Primary Headaches
Two other types of primary headaches (which occur rarer than migraines and tension-type headaches) show different characteristics. These are hemicrania continua, and chronic cluster.
Hemicrania continua (hemicrania means half-headed and continua means continuous) is strictly a one-sided headache which can wax and wane in intensity without resolving. It does not include migraine’s usual associated symptoms of nausea, light sensitivity, sound sensitivity and exertional aggravation.
Chronic cluster, like its less frequent episodic form, involves intense, recurring pain in or around just one eye that lasts for only 15 to 180 minutes per attack, but can occur more than once per day. Unlike its episodic cousin, chronic cluster does not go into remission without treatment.
Secondary headaches taking the form of CDH can have many causes, such as…
- head injury;
- arthritis of the neck bones;
- arthritis of the jaw joints (TMJs);
- sinus disease;
- breathing problems during sleep;
- tumors or other conditions causing increased pressure within the braincase;
- leakages of the cerebrospinal fluid that surrounds the brain and spinal cord;
Two types of secondary CDH deserve special mention in particular: giant cell arteritis and medication overuse headaches.
Giant cell arteritis (previously called temporal arteritis) occurs in people who are at least 50 years old and becomes more common in subsequent decades of life. It involves inflammation of larger-diameter arteries supplying blood to the brain and the rest of the head and – if left untreated – can lead to stroke or blindness. So, it’s important to recognize and treat this type of headache before complications happen.
Classically, people with giant cell arteritis show a swollen, stiff, tender artery just beneath the skin of one or both temples.
When this happens, it facilitates diagnosis, but GCA can still be present in the absence of this telltale sign. As a rule of thumb, GCA should be considered as a possible diagnosis in every new headache disorder starting at the age of 50.
Medication overuse headaches (also known as rebound headaches) occur when a primary headache disorder transforms into an even worse secondary headache disorder via too many doses of as-needed medication.
Typically, the primary headache disorders involved are either migraine or tension-type headaches, and the transformation occurs when the headache sufferer takes need-driven medication for them at least 2 to 3 days each week.
When the as-needed medication is a painkiller this syndrome is called analgesic rebound and when a triptan drug is used, it is called triptan rebound. The thing with medication overuse headaches is that they don’t get better until the drug that caused them is withdrawn and – even then – can take up to two months to wash out.