What's the Difference Between Headache and Migraine?

A headache is just an aching head, right? Anyone who has experienced a migraine or cluster headache will tell you that's not the case. We explore the differences between migraines and headaches to better understand the symptoms and when you should consider getting care.

What is a headache?

It's safe to say that most people will experience a headache at least once during their lifetime. For some, headaches are a chronic challenge.

Headaches can be considered primary or secondary. Secondary headaches are uncommon, as they are caused by other conditions that are potential medical emergencies — brain tumors, bleeding in the brain, nervous system infections such as encephalitis or meningitis.

But what most of us think of when we think "headache" is a primary headache: 98% of headaches are considered primary, meaning they have no underlying cause, whether it is a disease or an injury.

Dr. Stacy Smith, a neurologist and headache specialist at Houston Methodist, notes that the International Classification of Headache Disorders (ICHD) lists three main categories of primary headache disorders: migraine, tension headache and cluster headache.

Is a migraine different than other types of headaches?

People might use the word "migraine" as a synonym for a "terrible headache." However, Dr. Smith says that there is a constellation of symptoms that lead to a diagnosis of migraine.

"Migraine is typically one-sided, throbbing or pulsating in quality, moderate to severe in intensity and associated with an intolerance of routine activities," Dr. Smith says. "People will also have nausea, vomiting or sensitivity to lights and noises. Someone can have all of those symptoms, but of those first four things I mentioned, you must have two, and then you should have nausea, vomiting, or light or noise sensitivity. That's what gets you the migraine diagnosis, and within migraine, there's with and without aura."

An aura is a visual disturbance where someone can see a C-shaped, shimmery light area while experiencing a migraine. Dr. Smith says that an aura can also look like temporary vision loss that grows and then moves out of the visual field over five minutes to an hour.

So what about other types of headaches?

Tension headache

Tension headaches are by far the most common type of headache disorder people. And while Dr. Smith says there's no such thing as a "normal headache," the symptoms of a tension headache — constant dull pain or pressure, aching or tight muscles in the neck and shoulders and a "head in a vice" feeling, like someone is pressing on both the ears — are hallmarks of what most people consider headaches. Tension headaches can also come with sensitivity to sound or light, but unlike migraines, there is no nausea or vomiting and no visual disturbance symptoms such as aura.

"Tension headaches are kind of everything a migraine isn't," Dr. Smith says. "It's mild to moderate in pain. It's considered non-disabling, non-pulsating and typically bilateral, meaning it affects both sides of the head."

Dr. Smith also says that while tension headache is the most common disorder, it's likely underdiagnosed. That's because someone can usually continue their normal activities while experiencing a tension headache and get relief by simply taking an over-the-counter pain reliever, such as aspirin or ibuprofen.

"Because it is not as disabling as migraine, it's not as commonly seen in clinical practice," Dr. Smith says. "Tension headache is incredibly prevalent in the world, but migraine is what we see most commonly in our clinics because those folks are more likely to go to a doctor."

Cluster headache

Cluster headache is a much less common headache disorder overall. Cluster headaches are the most common headache disorder within a headache group called trigeminal autonomic cephalalgias. This unique headache type is defined by its timing, Dr. Smith says.

The "cluster" definition comes from the fact that these headaches will happen on a very strict schedule of anywhere from a few weeks to a few months and then the headaches disappear. People who suffer from cluster headaches can then go for weeks, months or even years without one before the next cycle begins, according to Dr. Smith.

"It is on a schedule, and the timing of a cluster headache is about an hour," Dr. Smith says. "It comes on very abruptly, lasts the hour, then goes away — and it's always at the same time every day, or close to it. It's usually around 3 a.m. Boom, you get an excruciating headache, it gets you out of bed. You're restless or agitated; it lasts about an hour and goes away. And this is going to happen night after night for several weeks or months."

Cluster headaches are excruciatingly painful for patients, Dr. Smith says. The pain is strictly unilateral on one side of the head and should never cross to the other side. It always happens in the same spot, typically around the eye.

"Almost everyone describes it like a hot poker stabbing through their head," Dr. Smith says.

Can you tell what kind of headache you have?

It can be challenging for people to distinguish the type of headaches they're experiencing for a variety of reasons. For one, Dr. Smith says it can be easy to confuse headache terminology, which may lead a primary care provider down the wrong path.

"I always see cluster headache diagnosed incorrectly," Dr. Smith says. "Migraines come at very irregular intervals. It would be helpful if they were predictable, but people will go a long time without any, and then boom, they'll have a bunch in a row. Patients will then call it 'clustering' and use that term, but true cluster headache is a very different disorder, and it's much less common."

"Interestingly enough, a lot of cluster headache patients have been called migraine patients, but so many of the migraine patients will get labeled cluster headache patients," adds Dr. Smith. "And it's just because people don't know the terminology."

Additionally, our grin-and-bear-it culture can lead people to minimize their symptoms, especially if they are able to keep up with work, family and social obligations.

"Migraine gets misdiagnosed both ways," Dr. Smith says. "People will talk about their 'normal headache.' Well, there is no such thing as a normal headache. And when you really tease it out, they actually do have a lot of the features of migraine, enough to meet the diagnostic criteria. It's just not always as severe, and they will really fixate on the one that was bad enough they missed work or had to cancel an event. But it turns out a lot of what people are calling tension headache really is migraine, and they're simply downplaying it."

Dr. Smith also emphasizes that it's not always black and white with headache disorders — people can experience symptoms on a spectrum. They can show symptoms of tension headache and migraine, and it's possible someone's diagnosis may change over time.

"It's important to kind of throw out the preconceived notion of what you think you have," Dr. Smith says. "They're a 'normal headache,' 'they're genetic,' or 'they're migraine.' I have the patient describe their symptoms, and from there, we decide the label we're going to use. The patient may continue calling it what they want to, and they likely will, but we want to have a real understanding of what the condition is so we can pick the best treatment strategy."

When to get care for headache

A headache is usually not a medical emergency. However, a trip to the emergency room may be necessary if:

• A very painful headache comes on suddenly without warning
• A headache occurs along with confusion, difficulty speaking, double vision, fever, numbness, a stiff neck, seizures, weakness
• A headache happens after hitting your head, especially if the pain gets worse

Dr. Smith says that there is no definite line in the sand when someone should see a headache specialist. Having headaches is not normal, according to Dr. Smith, and she says there are many treatment options available to prevent them.

So if you're living with headaches multiple times a month, you may want to begin thinking about preventive treatment.

"My threshold for migraine patients is when they're having one a week, and for tension headache patients if they're reaching for medicine more than one or two days a week," Dr. Smith says. "At that point, they should be thinking about what else could we be doing to prevent the headaches instead of reaching for acute treatment."

Overusing over-the-counter medicines can have serious consequences, Dr. Smith emphasizes. Chronic use of pain relievers can lead to stomach ulcers and can cause serious damage to the liver and kidneys. And to add insult to injury, pain reliever overuse can make your headaches worse.

"If you're reaching for over-the-counter medicine frequently, there's a risk of your headache disorder progressing and becoming worse," Dr. Smith says. "It's called medication overuse headache. Patients may not realize when the treatment became the cause, when they're taking too much."

When someone has a migraine, they can't tolerate activity, can't work or do much of anything while it's active. But Dr. Smith says that tension headaches can also affect your day-to-day life.

"If tension headaches are frequent, multiple days a week, they're starting to impact quality of life," Dr. Smith says. "Maybe they can still go to work, but they're not as productive. They didn't do everything they wanted to do around the house and with the family. It can affect our relationships because you feel cranky. It would be better to get help."