What is a headache?
A headache, or cephalgia, as it is scientifically known, refers to any pain occurring in the region around the head of the neck. In most cases, this pain is a symptom attached to a condition around the neck or the head.
A headache can be a result of a number of causes some of which are benign with some being serious. The brain tissue does not have pain receptors and the pain felt is usually as a result of a disturbed pain-sensitive structure. There are nine regions in the brain which have the pain-structure that result in headaches. These regions include the muscles, cranium, veins and arteries, nerves, ears, eyes, sinuses, mucous membrane and the subcutaneous tissues.
In simple terms, a headache is referred to as a no-specific symptom. This means that there are many causes behind a headache including and not limited to dental or sinus issues, head injury, common cold, viral infection, medication side effects, stress, sleep deprivation, fatigue and even a fast ingestion of a really cold beverage or food among many others.
There are over two hundred headaches and while some are harmless, some are more serious and can be life-threatening. A neurological examination combined with the description of the headache is used in the determination of whether there is a need for more tests and the treatment direction to be taken.
Primary and Secondary Headaches
Broadly, headaches fall under a classification of either primary or secondary headaches. A primary headache is mostly benign, recurrent and the underlying cause is not a structural problem or a disease. A good example of a primary headache is a migraine. Albeit a primary headache can be the source of disability and daily pain, it is not life-threatening. Secondary headaches are types of headaches that result from an underlying condition or disease such as an infection, brain bleed, tumors, head injury or vascular disorders. A secondary headache ranges from harmless to extremely dangerous with certain symptoms being warning signs of a life-threatening headache.
About 90% of the headaches people experience are primary headaches. Primary headaches are mostly first experienced when an individual is between the age of 20 and 40 years. Migraines and some tension-type headaches are the most common primary headaches and come with different characteristics. Migraines are characterized by a pulsing pain in the head, photophobia, phonophobia and nausea. Tension-type headaches are characterized by a band-like pressure felt on both sides of the heads and there are no other symptoms. Some of the other types of primary headaches which are not as common as the two mentioned above are cluster headaches, TMJ, Occipital Neuralgia and Trigeminal Neuralgia.
A secondary headache refers to the pain in the head caused by a problem in the head or in the neck. Some secondary headaches are life-threatening such as cervicogenic headaches which are pains resulting from muscles of the neck. When headache medication is overused, this might lead to medication headache which is just the worsening of the headache. Some of the more serious secondary headache causes include subarachnoid hemorrhage, meningitis, brain tumors, acute closed angle glaucoma, and temporal arteritis.
The brain itself cannot sense pain because it does not have nociceptors or pain receptors. Though this is the case, there are a number of areas around the head and the neck which have pain receptors. These areas include the neck and head muscles, meninges, cranial and spinal nerves, venous sinuses, large veins, middle meningeal artery, extracranial arteries falx cerebri, eyes, teeth, mouth lining, ears, and parts of the brain stem.
A headache will often result fro the irritation or traction to the blood vessels and the meninges. Nocicetors can be stimulated by tumors, head trauma, dilated blood vessels, blood vessel spasms, muscular tension and the infection or inflammation of the meninges. When stimulated, the nociceptors will send a pain message to the brain and this is what brings about the headache.
The understanding of primary headaches is more complex that that of secondary headaches. The exact root causes of tension headaches and migraines are not known though there are different theories that have attempted to explain the mechanism behind these headaches.
Types of Headaches
Dangerous Headache Warning Signs
Sometimes it is difficult to tell a harmless headache from a life-threatening one because most of the symptoms are similar. The more dangerous headaches diagnosis requires more advanced lab tests and some imaging. Some of the red flags associated with dangerous secondary headaches include:
- Systematic disease (Malignancy, HIV infection)
- Systematic symptoms (weight loss or fever)
- Onset sudden (thunderclap headache)
- Neurologic signs or symptoms
- Previous history of headaches
Most headaches that people experience can be diagnosed based on the patient’s clinical history alone. If the physician classifies the symptoms described by the patient as being dangerous, there will be further testing and lumbar puncture or neuroimaging might be necessary.
The first step in the diagnosis of a head ache is to determine whether it is a new or an old headache. A new headache is described as a headache that has recently started or a chronic headache that has had a change of character recently. A good example is when a person has a chronic headache with pressure on both sides and the headache changed suddenly to throbbing pain on one side; this is referred to as a new headache. On the other hand old headaches are mostly primary headaches and are not dangerous. This means that migraines and tension headaches are old headaches.
It is highly recommended that when a person experiences recurring headaches they seek medical attention. Normal headaches can be treated using the normal painkillers but when the pain is recurring this might be a serious issue that needs urgent medical attention after tests. Some people surfer from headaches that result from medication which was misused in treating an old headache.