Most headaches are harmless, even when they feel awful. Over 90% of headaches fall into a category called “primary headaches,” meaning the headache itself is the problem, not a sign of something else going on in your body. The three most common types are tension headaches, migraines, and cluster headaches, and each one feels distinctly different. Understanding the pattern, location, and accompanying symptoms of your headache can tell you a lot about what’s causing it and whether you need to take action.
Tension Headaches: The Most Common Type
If your headache feels like a band of pressure squeezing both sides of your head, you’re likely dealing with a tension-type headache. The pain is mild to moderate, pressing or tightening rather than throbbing, and it doesn’t get worse when you walk up stairs or move around. You won’t feel nauseous, and light and sound don’t typically bother you the way they would during a migraine.
Tension headaches often show up after long stretches of screen time, poor sleep, stress, or holding your neck and shoulders in an awkward position. They can last anywhere from 30 minutes to several hours and usually respond well to over-the-counter pain relievers, rest, or simply addressing whatever triggered them. Eyestrain headaches feel similar but tend to settle in the front of the head on both sides, and they usually ease up once you step away from close-focus work.
How Migraines Feel Different
Migraines are more than a bad headache. They typically produce throbbing pain on one side of the head, though the pain can shift or spread across both sides. What sets migraines apart is everything that comes with them: nausea, vomiting, and intense sensitivity to light and sound. Most people with a migraine instinctively want to lie down in a dark, quiet room, and physical activity makes the pain worse.
A migraine can last an entire day, or stretch across several days if untreated. Many people also experience phases before and after the headache itself. In the hours or even a day before pain starts, you might notice mood changes, food cravings, frequent yawning, neck stiffness, or unusual fatigue. These early warning signs are called the prodrome phase. About one in four migraine sufferers also experiences an aura: visual disturbances like flashing lights, shimmering patterns, or blind spots that build over five minutes or so and last up to an hour. After the headache finally fades, a “migraine hangover” can linger, leaving you with fatigue, body aches, difficulty concentrating, and continued light sensitivity.
Common Migraine Triggers
Migraines have a long list of known triggers, and they vary from person to person. Common dietary triggers include aged cheese, chocolate, citrus, nuts, bananas, and processed foods containing nitrites, nitrates, or MSG. Environmental factors like bright light, strong scents, smoke, humidity, and cold weather can also set one off.
Hormonal changes play a major role, especially for women. Shifts in estrogen levels tied to menstrual cycles are one of the most reliable migraine triggers, and some women first develop migraines during perimenopause as estrogen levels become less predictable. Estrogen-containing medications can trigger them too.
Cluster Headaches: Intense but Short
Cluster headaches are less common but dramatically painful. The pain is excruciating, concentrated around or behind one eye, and lasts 30 to 90 minutes. Unlike migraines, where you want to lie still, cluster headaches make people restless and agitated. The affected eye often turns red, tears up, and the nostril on that side may become congested or runny.
These headaches arrive in “clusters,” striking one or more times daily for weeks or months, then disappearing entirely for long stretches. They tend to be seasonal, often flaring up in spring or fall. Researchers believe something in the environment triggers these cycles, though exactly what remains unclear.
What Your Headache Location Can Tell You
Where the pain sits offers useful clues, though it’s not a perfect diagnostic tool on its own.
- Both sides of the head, band-like pressure: tension-type headache
- One side, throbbing: migraine
- Around or behind one eye, severe: cluster headache
- Temples, with jaw tightness: jaw joint dysfunction (TMD), common in people who clench or grind their teeth
- Front of the head, both sides: eyestrain or fasting headache
- One side of the head with a stiff neck, pain radiating to the shoulder or arm: cervicogenic headache, meaning the pain is actually coming from your neck
Headaches From Taking Too Much Pain Medication
This is one of the most common and most overlooked causes of frequent headaches. If you’re reaching for pain relievers on 10 to 15 or more days per month for three months or longer, the medication itself can start causing headaches. The International Headache Society defines medication overuse headache as headache occurring on 15 or more days per month as a direct consequence of this pattern.
The exact threshold depends on the type of medication. Simple pain relievers like ibuprofen carry a threshold of 15 days per month, while combination medications and triptans can cause rebound headaches at 10 days per month. The cruel irony is that the headache from overuse feels similar to the original headache, so people take more medication, deepening the cycle. Breaking the cycle usually means gradually reducing the medication, which temporarily worsens headaches before they improve.
Red Flags That Need Urgent Attention
Primary headaches are unpleasant but not dangerous. Secondary headaches, caused by an underlying condition, are far less common but sometimes serious. The characteristics below are what clinicians use to distinguish one from the other, and knowing them can help you decide whether your headache warrants a call to your doctor or a trip to the emergency room.
Sudden, explosive onset. A headache that hits maximum intensity within seconds to minutes, sometimes called a thunderclap headache, is one of the most concerning headache features. It can signal a ruptured blood vessel in the brain and needs immediate evaluation.
Neurological symptoms. Primary headaches don’t typically cause weakness in an arm or leg, new numbness, slurred speech, or sudden vision changes outside of a known migraine aura pattern. These symptoms alongside a headache suggest something is affecting the brain directly.
New headaches after age 50. Most primary headache disorders begin earlier in life. A brand-new headache pattern starting after 50 is more likely to have a secondary cause, including inflammation of blood vessels in the temples (which can threaten vision if untreated).
Fever, weight loss, or night sweats. Headache combined with signs of systemic illness may point to infection or another condition that needs treatment.
Headache that keeps getting worse. Primary headaches tend to come and go. A headache that progressively intensifies over days or weeks, or one that’s becoming more frequent over time without an obvious explanation, is worth investigating.
Headache that changes with position. Pain that dramatically worsens when you stand up or lie down can indicate a pressure problem inside the skull, such as a spinal fluid leak.
Headache triggered by coughing, straining, or exercise. While exertion headaches can be benign, this pattern sometimes points to a structural issue that needs imaging to rule out.
New headache during or after pregnancy. Hormonal changes make headaches common in pregnancy, but new or unusual headache patterns in pregnant or postpartum women can signal blood pressure complications or vascular problems that require prompt attention.
When Imaging Is and Isn’t Needed
If your headache fits a recognizable primary pattern, like tension headaches or migraines with your usual symptoms, and your neurological exam is normal, brain imaging is generally unnecessary. The American College of Radiology states that neuroimaging is “usually not appropriate” for uncomplicated primary headaches.
Imaging becomes appropriate when red flags are present: a sudden severe headache reaching peak intensity within an hour, headaches with fever or neurological deficits, a history of cancer or immune compromise, new headaches after age 50, headaches following head trauma, or headaches that are clearly increasing in frequency or severity. In those situations, a CT scan or MRI can rule out structural problems, bleeding, or other serious causes. Your doctor will choose based on the specific concern: CT scans are faster and better at detecting fresh bleeding, while MRI provides more detailed images of brain tissue.