What Can Cause Headaches - And How to Find Out Which Trigger Is Yours

Headaches are one of the most common health complaints in the world. According to the World Health Organization, almost half the adult population has a headache at some point in any given year. More recent global burden data suggests headache disorders now affect roughly 3 billion people worldwide.

So you are definitely not alone. But that number also points to the problem: when something is this common, the list of possible causes is long - and knowing that "stress or dehydration" might be behind your headache doesn't actually tell you which one is behind yours.

This article covers the main causes of headaches, then shifts to the more useful question: how do you figure out which triggers are specific to you?

What are the most common types of headaches?

There are two broad categories of headache. Primary headaches are not caused by an underlying medical condition - the headache itself is the condition. Secondary headaches are a symptom of something else, such as a sinus infection, high blood pressure, or a medication effect.

The most common primary headache types are:

• Tension headaches - the most frequent type. A dull, pressing pain around the head, often described as a tight band. Usually triggered by muscle tension, stress, or fatigue.
• Migraines - typically one-sided, throbbing pain, often with nausea, light sensitivity, or visual disturbances. More complex in origin and often involve multiple overlapping triggers.
• Cluster headaches - severe, piercing pain on one side, usually around one eye. Much less common, but intensely painful and often occurring in clusters over weeks.
• Cervicogenic headaches - pain that originates in the neck and refers up into the head. Often linked to posture, muscle tension, or neck injury.

Most people experience tension headaches or migraines, so that's where the bulk of this article focuses.

What can cause headaches? The main trigger categories

Headache triggers fall into several broad groups. Most people's headaches involve more than one of these at the same time.

Lifestyle and stress factors

Stress is the most commonly reported headache trigger. Emotional stress causes muscles in the neck, scalp, and jaw to tighten, which can set off a tension headache directly. Lack of sleep - or irregular sleep patterns - is another major contributor. Even sleeping too much on a weekend can trigger what some call a "weekend headache."

Skipping meals or going too long without eating may also cause headaches through blood sugar changes. When blood glucose drops, the brain - which relies almost entirely on glucose - responds with physiological stress signals that can manifest as head pain.

Dehydration

Even mild dehydration may contribute to headaches. Research published in PMC (National Institutes of Health) suggests that reduced fluid intake can lower blood volume and cause slight changes in brain tissue, which activates pain-sensitive structures around the brain. Importantly, the exact mechanism is still not fully understood, but the association between poor hydration and headache is well-established clinically.

Food and drink

Certain foods and drinks are associated with headaches in some people. The most commonly cited include:

• Alcohol - particularly red wine. A meta-analysis cited by the American Migraine Foundation found that 35.6% of people with migraines reported alcohol as a trigger.
• Caffeine - both too much caffeine and caffeine withdrawal can cause headaches. This is why regular coffee drinkers often get a headache when they skip their morning cup.
• Aged cheeses, cured meats, and fermented foods - these contain tyramine and histamine, compounds associated with headache in sensitive individuals.
• Processed meats - contain nitrates and nitrites that may dilate blood vessels and trigger headaches in some people.
• MSG (monosodium glutamate) - reported as a trigger by some people, though research evidence is mixed.
• High-sugar or high-glycemic foods - may contribute to blood sugar swings that precede headache.

An important nuance: research from the American Migraine Foundation notes that many people wrongly attribute headaches to food they ate immediately before the pain started. In reality, the prodrome phase of a migraine can cause food cravings - so you may reach for chocolate or cheese because a headache is already beginning, then blame those foods when the headache arrives. Delayed reactions make food triggers particularly hard to self-diagnose without tracking.

Hormonal changes

Fluctuations in estrogen are a significant headache trigger, particularly for people who menstruate. Migraines often worsen around menstruation, improve during pregnancy for some people, and shift again around menopause. Hormonal contraceptives can also affect headache patterns.

Environmental and sensory triggers

Bright light, loud noise, strong smells, and changes in weather or barometric pressure are reported headache triggers. Screen time and fluorescent lighting are common workplace contributors.

Posture and physical factors

Poor posture - particularly extended time looking at screens with forward head position - creates sustained tension in the neck and upper back muscles that can refer pain into the head. This type of headache has become more common with the increase in desk work and phone use.

Medications

Ironically, frequent use of pain relief medications can itself cause headaches. This is called medication overuse headache (or rebound headache) and occurs when pain relievers are used on more than 10-15 days per month. The brain becomes sensitized, and withdrawal between doses triggers a new headache.

Why food and drink deserve special attention

Diet is one of the most underexplored headache triggers - not because it's more important than stress or sleep, but because the connection is genuinely harder to see.

Unlike a headache that clearly follows three hours of staring at a screen, food-related headaches often involve a delay. A reaction to tyramine in aged cheese or histamine in wine may not produce a headache until hours later. By then, you've eaten several other things, moved locations, and forgotten what you had for lunch. The connection never gets made.

This is compounded by individual variation. The National Headache Foundation notes that tyramine sensitivity is highly variable - some people can eat aged cheese without any effect, while others consistently react. The same is true for histamine, MSG, and nitrates. There is no universal food trigger for headaches. What matters is your specific pattern.

If you suspect food may be playing a role in your headaches, our detailed guide to why a food diary for headaches needs to track more than food covers what to log and how to find those delayed connections.

For people whose headaches may overlap with other food-related symptoms - such as bloating, fatigue, or brain fog - it may also be worth exploring food intolerance symptoms more broadly. Histamine intolerance in particular is often underrecognized as a cause of recurrent headaches.

The trigger threshold: why one cause is rarely enough

One reason headaches are so frustrating to understand is that a single trigger is often not enough to cause one. Many people have a headache threshold - a point at which the combined weight of several factors tips them into pain.

On a day when you slept badly, skipped breakfast, had two glasses of wine, and were under deadline stress, a headache is almost predictable. On a day when you had good sleep and a nourishing meal, that same glass of wine might have no effect at all.

This is sometimes called the "bucket model" of headache - individual triggers add fluid to the bucket, and when it overflows, you get a headache. No single trigger caused it; they accumulated.

This is why identifying your triggers requires looking at patterns over time, not just the hour before the headache started.

How to find your specific headache trigger

If you get headaches regularly and want to understand why, the most effective approach is systematic tracking. Here is a practical framework:

1. Track every headache for at least 4 weeks. One or two episodes are not enough to see a pattern. You need enough data points that genuine correlations become visible.
2. Log what you ate and drank in the 24 hours before each headache. Include timing. A reaction to yesterday's lunch can show up as today's headache.
3. Record sleep, stress level, and physical activity. These interact with food and drink triggers. Without them, you may blame food when sleep was actually the culprit.
4. Note the headache's characteristics. Location, quality (throbbing vs. pressure), severity, and how long it lasted. Different headache types may point to different causes.
5. Track your cycle if relevant. Hormonal headaches have a predictable timing pattern that becomes clear over a few months of data.
6. Look for patterns - not individual events. After several weeks, ask: do headaches cluster on particular days? After particular meals? During particular sleep patterns? After alcohol or caffeine withdrawal?

This kind of multi-variable pattern detection is exactly what DietSleuth is built for. The app logs your food, symptoms, sleep, and other lifestyle factors and uses AI to surface correlations you might not notice on your own - including delayed reactions where the connection between what you ate and how you felt might be 12 or 24 hours later.

Start Your Free Trial of DietSleuth

When should you see a doctor about a headache?

Most headaches are uncomfortable but not dangerous. However, some warrant prompt medical attention. Seek medical care if you experience:

• A sudden, severe headache described as "the worst headache of your life" (this can indicate a serious emergency)
• A headache with fever, stiff neck, confusion, or rash
• Headache following a head injury
• Headaches that are progressively getting worse over days or weeks
• New headaches after age 50
• Headache accompanied by neurological symptoms such as vision changes, weakness, or speech difficulty

Tracking your headaches is also useful for these medical conversations. A detailed log of frequency, severity, potential triggers, and what helps gives your doctor much more to work with than a vague description of "I get headaches sometimes."

Frequently Asked Questions

What is the most common cause of headaches?

Tension headaches are the most common headache type, and stress is their most frequently reported trigger. Poor sleep, dehydration, and muscle tension in the neck and shoulders are also among the most common contributing factors.

Can food cause headaches?

Yes, certain foods may trigger headaches in some people. Alcohol (especially red wine), aged cheeses, processed meats, caffeine, and high-histamine foods are the most commonly reported dietary triggers. However, food triggers are highly individual - what affects one person may have no effect on another, which is why personal tracking is more useful than avoiding a generic list.

How do I know if my headache is from dehydration?

A dehydration headache often improves within 30 minutes to 3 hours of drinking water. It is typically felt as a dull, diffuse ache rather than a throbbing or one-sided pain. If you rarely drink enough water and your headaches improve with hydration, dehydration is a likely contributor.

Can headaches be caused by food intolerance?

Possibly. Some people with food intolerances - particularly histamine intolerance or sensitivity to certain food chemicals - report headaches as a symptom alongside digestive issues, skin reactions, or fatigue. Tracking your food and symptoms together over several weeks is the most practical way to investigate whether there is a connection.

This content is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before making changes to your diet or health routine, particularly if your headaches are frequent, severe, or associated with other symptoms.

Sources

1. World Health Organization. Headache disorders. WHO Fact Sheet. https://www.who.int/news-room/fact-sheets/detail/headache-disorders
2. Institute for Health Metrics and Evaluation. Headache disorders affect 3 billion people worldwide. News Release, 2025. https://www.healthdata.org/news-events/newsroom/news-releases/headache-disorders-affect-3-billion-people-worldwide-nearly-one
3. Nakamura J, et al. Dehydration and Headache. PMC / National Institutes of Health, 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8280611/
4. American Migraine Foundation. Diet and Headache Control. https://americanmigrainefoundation.org/resource-library/diet/
5. National Headache Foundation. Low-Tyramine Diet for Individuals with Headache or Migraine. https://headaches.org/resources/low-tyramine-diet-for-individuals-with-headache-or-migraine/
6. National Headache Foundation. Tracking Diaries. https://headaches.org/resources/headache-diary-keeping-a-diary-can-help-your-doctor-help-you/
7. Slavin M, et al. Diet and Headache: Part 1. Headache, 2016. PubMed. https://pubmed.ncbi.nlm.nih.gov/27699780/
8. Stovner LJ, et al. The global prevalence of headache: an update. The Journal of Headache and Pain, 2022. https://link.springer.com/article/10.1186/s10194-022-01402-2