The Most Common Causes of Headaches, According to Doctors

There are few things that can ruin your day as quickly as a bad headache. But once you’ve determined what is causing your headache, you can figure out the best way to treat it. Here, doctors explain the number-one cause of headaches, share some of the health conditions that count headaches among possible symptoms, and say when you should call your doctor about your headaches.

Meet the experts: Medhat Mikhael, M.D., a pain management specialist and medical director of the Spine Health Center at MemorialCare Orange Coast Medical Center in Fountain Valley, Calif.; Shawn Conger-Love, M.D., a neurologist and headache specialist at the UCLA Goldberg Migraine Program in Los Angeles.

“A headache is any pain or discomfort in the head, face, or upper neck,” says Medhat Mikhael, M.D., a pain management specialist and medical director of the Spine Health Center at MemorialCare Orange Coast Medical Center in Fountain Valley, Calif. “Interestingly, your brain itself can’t feel pain; it doesn’t have pain receptors. Instead, headache pain comes from irritation or tension in the surrounding structures, including nerves, blood vessels, and muscles in the scalp, face, and neck.”

Read on for everything you need to know.

“Headaches come in many forms, but a few types account for the majority of cases,” says Dr. Mikhael. Here are the ones you should be aware of.

Tension headaches

“Tension headache is the most prevalent primary headache disorder,” says Shawn Conger-Love, M.D., a neurologist and headache specialist at the UCLA Goldberg Migraine Program in Los Angeles. “It is characterized by a dull, pressure sensation in a classically band-like distribution around the head.”

The direct cause of tension headaches is still not clearly understood. However, Dr. Mikhael says they are often linked to stress, poor sleep, eye strain, dehydration, skipping meals, caffeine withdrawal, or poor posture (or more than one of the above). Coexisting migraines, fatigue, anxiety, and depression may also contribute to tension headaches, according to a study in Headache and Pain Research. “[These triggers] are thought to increase sensitivity of pain receptors in the muscular structures around the head that then lead to chronic pain signals in the brain,” Dr. Conger-Love explains.

Migraine headaches

After tension headaches, migraines are the second most common type of headache. “Migraine is a debilitating primary headache disorder characterized by episodic attacks of a severe, throbbing headache, often experienced on one side of the head and associated with nausea, light and/or sound sensitivity, and avoidance of routine activities,” says Dr. Conger-Love.

Unlike tension headaches, whose cause typically comes from outside the brain, migraines originate within the brain itself. “Patients with migraine have hyperexcitable brains that generate a cascade of neurochemical changes, which lead to the dramatic symptoms experienced by its sufferers,” Dr. Conger-Love explains. These changes may include activation of the trigeminal nerve, a major pain pathway in the face and head, changes in brain chemicals like serotonin and CGRP, and temporary inflammation in the blood vessels of the brain, according to Dr. Mikhael. Still, there are outside triggers that ultimately cause the changes in the brain that lead to migraine symptoms. Per the American Migraine Foundation, the most common migraine triggers are stress, changes in sleep schedule, hormones, caffeine and alcohol, changes in the weather, diet, dehydration, light, and smells.

Medication overuse headaches

Also called rebound headaches, “these are caused by frequent use of pain medications, which can actually worsen headaches over time,” says Dr. Mikhael. According to the National Library of Medicine, these tend to occur in people who already have migraines or frequent tension headaches, though if you are prone to headaches and use pain medication for another condition you may also develop a rebound headache. In folks with migraines, taking acute pain meds (as opposed to preventative medication) more than 10 days out of a month can cause medication overuse headaches, per the American Migraine Foundation.

Cervicogenic headaches

If you have a muscle strain or joint problem in your neck, it can lead to cervicogenic headaches, says Dr. Mikhael. In these cases, pain from an injury to your neck or cervical spine radiates up to your head, according to the Cleveland Clinic. It often starts at the base of your skull and pulses up one side of your head and can limit the range of motion in your neck.

Sinus headaches

“Sinus headaches are typically caused by inflammation or blockage in the sinus cavities, most often due to sinus infections (sinusitis),” Dr. Mikhael says. “When the sinuses become swollen and filled with fluid, it creates pressure that can lead to pain in the forehead, cheeks, and around the eyes.” That said, you may experience pain in this area even if you don’t have a sinus infection. “Many types of headaches may cause pain in the sinus region because they affect the trigeminal nerves, which are responsible for pain sensation in the face,” Dr. Conger-Love explains.

While plenty of people suffer from headache disorders or frequently experience the types of headaches mentioned above, headaches may also be a symptom of a variety of other health conditions, some of which affect the brain and some of which do not.

According to Dr. Mikhael and Dr. Conger-Love, all of the following health conditions count headaches among their possible symptoms: high blood pressure, viral illnesses like the flu or COVID-19, infections like meningitis or encephalitis, autoimmune diseases like rheumatoid arthritis or lupus, thyroid disorders, diabetes, neurological conditions like multiple sclerosis, dehydration, vascular disorders, changes in cerebrospinal pressure, alcohol use, and caffeine withdrawal. And yes, headaches are also the telltale sign of a brain tumor—though headaches caused by a brain tumor are unusual for you, clearly different from prior headaches, and continue to worsen over time.

“Most headaches are not dangerous, but certain ‘red flags’ signal the need for urgent medical attention,” says Dr. Mikhael. If your headache is accompanied by one or more of the following, Dr. Mikhael and Dr. Conger-Love suggest seeking care right away:

• Fever
• Numbness, weakness, or difficulty speaking
• Being over 50 with a new headache
• The onset of the headache is sudden and severe
• A significant change in frequency, severity, or character of pain
• Worsening pain over time
• Changes in pain based on body position (such as lying flat or standing up)
• Vision loss or changes in vision

“These symptoms may indicate a more serious condition, such as infection, bleeding, or a neurological issue,” Dr. Mikhael says. “In many cases, headaches are harmless, but persistent or unusual headaches should be evaluated.”