Cephalgia · What Is It, Types, Causes, and More

Cephalgia, more commonly known as a headache, includes any type of pain affecting the head, face, or neck. Headaches can be categorized into primary or secondary types. 

A primary headache, while painful, usually is not dangerous and has no relationship to an underlying disease or structural abnormality. Since the brain cannot “feel” physical sensation, any pain associated with a primary headache comes from inflammation of the nerves, blood vessels, and muscles surrounding the head, face, or neck. 

Secondary headaches typically have a sudden onset and are extremely painful. These are often a result of an underlying illness or trauma that triggers pain-sensitive areas in the head, neck, or face. Secondary headaches are less common than primary headaches, but they tend to be much more serious and involve additional symptoms due to the underlying illness.

Cephalgia may be caused by a variety of factors, depending on whether an individual is presenting with primary or secondary cephalgia. Primary cephalgia can be attributed to a wide range of risk factors, including family history, advanced age, and disorders of the head, neck, or face. Increased stress, poor diet, dehydration, consumption of certain kinds of alcohol, too much or too little sleep disturbances, hormonal changes, and certain medications can also be factors. Changes in the weather and exposure to bright, pulsating lights are environmental factors that may induce or worsen a headache. Individuals may be at higher risk for specific types of primary cephalgia depending on their age and sex. 

Meanwhile, secondary cephalgia can be caused by a brain tumor, infection, brain bleed, injury or trauma to the neck or brain, or other medical conditions. Secondary cephalgia can also be a side effect of certain medications, sleep apnea, carbon monoxide poisoning, oxygen deprivation (i.e., hypoxia), and recreational drug or alcohol usage. 

Primary cephalgia is generally acute, occurring suddenly for a relatively short period of time. Among the several types of acute cephalgia, tension and migraine headaches are the most common. Tension headaches are characterized by a mild or moderate pain around the entire head, similar to the feeling of a tight elastic band around the head. Tension headaches may be treated with rest, hydration, and non-prescription pain-relieving medications, like acetaminophen or ibuprofen. 

Migraine headaches result from a sensitivity to movement, light, or other triggers. In addition to the pain, other symptoms of migraines can include fatigue, nausea, dizziness, visual disturbances, and irritability. Rest in a dark, quiet space, massage, application of hot or cold compresses, and pain-relieving medications may help alleviate migraines. Both over-the-counter medications, particularly anti-inflammatory drugs, and prescription medications, such as triptans, have been used to reduce migraine pain. However, frequently taking these medications to treat migraines can result in migraines occurring more often.

Other types of acute headaches include cough-related headaches, headaches due to physical activity, trigeminal autonomic cephalgia (TAC), trigeminal neuralgia, hypnic headaches, and cold stimulus headaches.

Trigeminal autonomic cephalgia (TAC) is a type of primary headache characterized by intense pain on one side of the head in the area where the trigeminal nerve is located. TAC may cause autonomic symptoms -- watering eye, red eye, drooping eyelid, and leaking nose -- on the same side of the head where the pain occurs. The duration and frequency of TAC episodes vary depending on the type. 

Types of TAC include cluster headaches, hemicranial headaches, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). Cluster headaches, which are characterized by severe pain that is localized to the eye or temple on one side of the head, are the most commonly occurring TAC.