Headaches are one of the oldest recorded ailments, with treatments dating back to ancient Greece. Back then, patients prayed to Asclepius, the god of medicine, for relief, and if that didn’t work, doctors might perform trepanation—drilling a small hole in the skull to release “infected” blood. Thankfully, modern medicine has advanced far beyond such extreme measures, but headaches remain a common and often misunderstood condition.
Let’s dive into what causes headaches, how they’re classified, and what we can do about them.
Types of Headaches: Primary vs. Secondary
Headaches fall into two main categories: primary headaches and secondary headaches. The difference between the two lies in their cause:
- Primary headaches: These are headaches that aren’t caused by another health condition. They are the condition itself. Examples include migraines, cluster headaches, and tension headaches.
- Secondary headaches: These headaches are symptoms of an underlying issue, such as dehydration, caffeine withdrawal, head injury, or even heart disease. In these cases, the headache is your body’s way of signaling that something else is wrong.
While primary headaches make up about 50% of all reported cases, we know more about secondary headaches because their causes are easier to identify.
What Causes Secondary Headaches?
Secondary headaches are triggered by other health problems, and doctors have classified over 150 types. One common example is a headache caused by a sinus infection. Here’s what happens:
- Sinus infection: The sinuses are cavities located behind your forehead, nose, and cheeks. When they become infected, your immune system responds by increasing the temperature in the area to fight off the bacteria. This causes inflammation, which enlarges the sinuses and puts pressure on nearby arteries, veins, and muscles.
- Pain receptors: The pressure on the muscles and blood vessels activates pain receptors called nociceptors, which send signals to the brain. In response, the brain releases neuropeptides that further inflame the blood vessels, leading to the throbbing pain we associate with a headache.
Not all headaches caused by secondary factors involve swelling. For example, tension in the muscles or sensitive nerves can also lead to varying degrees of pain.
What Causes Primary Headaches?
While the causes of secondary headaches are easier to pinpoint, primary headaches remain more mysterious. Scientists are still investigating what triggers primary headaches, including:
1. Migraines
Migraines are severe, recurring headaches that can last anywhere from four hours to three days. About 20% of migraine sufferers experience auras, which are visual or sensory disturbances caused by an overload of electrical activity in the brain. People with migraines may see flashing lights or geometric patterns, and some even feel tingling sensations.
2. Cluster Headaches
Cluster headaches are another type of primary headache. These are characterized by sharp, stabbing pain behind one eye, often leading to a red eye, drooping eyelid, and a constricted pupil. The pain is intense and comes in quick bursts, making it one of the most painful types of headaches.
3. Tension Headaches
Tension headaches are the most common type of primary headache and create the feeling of a tight band squeezing around the head. Stress, dehydration, and hormone changes are often reported as triggers, but the exact cause is still debated. Some scientists suggest that spasming blood vessels or overly sensitive nociceptors could be to blame.
How to Treat Headaches
The best way to treat a headache depends on the type:
- Tension headaches and most secondary headaches can usually be relieved with over-the-counter medications like ibuprofen or acetaminophen. These medications work by reducing inflammation in the blood vessels around the head.
- Lifestyle adjustments: Secondary headaches caused by triggers like dehydration, eye strain, or stress can often be prevented by staying hydrated, taking breaks from screens, and managing stress levels.
- Migraines and cluster headaches, however, are more complex. While over-the-counter medications may help some people, others need prescription drugs, and even those may not work for everyone. Research is ongoing to find more effective treatments for these debilitating headaches.
The Future of Headache Research
Although headaches are common, much remains unknown, particularly about primary headaches like migraines and cluster headaches. Fortunately, neurologists and pharmacologists continue to study these conditions, searching for better treatments and cures. In the meantime, understanding the different types of headaches and their causes can help you manage your symptoms and find relief.