Headaches are a very common symptom. Unfortunately, they can be caused by many things, making them difficult to treat. In this article, I'm going to cover what I believe are the most common causes of headaches, and it should help many people manage this potentially debilitating condition.
90% of headaches are classified by 4 subgroups, including migraine, tension, cluster, and medication overuse. (R)
Migraines are a more severe form of headache. Persons suffering from migraines may have severe throbbing pain on one or both sides of the head, nausea, vomiting, and sensitivity to light and sound. The symptoms are enough to be disabling.
Aura can occur before or during a migraine. Auras are visual disturbances, such as seeing flashes of light, zigzag vision, blind spots, or a tingling sensation on one side of the face, arm, or leg. However, only 1/3 of persons will have auras with migraines. (R)
After the migraine is gone, some may be confused, dizzy, weak, and worn out.
Symptoms of migraine (R)
- Pain on one or both sides of head
- Throbbing pain
- Sensitivity to light, sounds, smells, and touch
- Nausea and vomiting
- Visual disturbances
- Nasal congestion and discharge
- Neck pain
The first thing to understand about the causes of headaches is that they are caused by both internal and external triggers. Meaning, headaches can be caused by things outside of our bodies, such as chemical scents, and also by things inside our bodies, such as low blood sugar.
Migraines are usually diagnosed by medical history, and the most common symptoms are disability, nausea, and photophobia. Blood tests may be used to check for infections and toxins. An MRI or CT scan may be used to look for tumors, strokes, and other brain abnormalities to rule them out. (R)
The truth is, most people know if they have headaches or migraines, so when people go to the doctor, they are usually making sure it’s not something more serious and trying to get medication for the pain so they can function.
Migraines can be hereditary. If you’re parents or other family members suffer from headaches, you may be at an increased risk of getting headaches as well. This doesn’t necessarily help you much, it’s just a way to understand why you may be getting headaches. (R)
This can be a good thing, because if you figure out something that helps you, it could potentially help your other family members.
In my opinion, blood sugar dysregulation is likely the most common cause of headaches.
Not eating for longer periods of time (fasting) and hunger are common triggers of headaches. People with low blood sugar (hypoglycemia) are more likely to suffer from headaches. Hypoglycemia can occur in the middle of the night while you are sleeping. Many people wake up with headaches often, and I strongly believe that the headaches are caused by poor blood sugar regulation throughout the night.
If you wake up with headaches, try eating a snack before bed. You should not be hungry when you go to bed, especially if you have poor blood sugar regulation. (R)
High blood sugar and insulin resistance are associated with migraines. Persons with migraines have been found to have higher levels of both insulin and fasting glucose. Higher insulin levels can increase the amount of free fatty acids and blood lipids, which may be a mechanism that causes headaches. (R)
To keep your blood sugar stable, in simple terms, you’ll need to eat less processed carbohydrates, eat more vegetables and fruit, and make sure you are eating enough, and often enough.
You can read more about methods to stabilize your blood sugar here.
Inflammation from food sensitivities and intolerances are likely the second most common cause of headaches.
When patients follow an elimination diet that removes foods they have IgG antibodies to, they have a significant reduction in headaches. (R)
Headaches are a common symptom of food sensitivities. While pretty much any food can cause a headache, there are specific foods which tend to give people the most trouble and are more likely to cause a reaction.
Foods likely to cause headaches
- Grains, particularly wheat and other gluten containing grains
- High histamine foods
- Charred meat, or meat cooked at very high temperatures
- Nightshades (tomatoes, eggplant, peppers, potatoes)
- High salicylate containing foods
- Nuts and seeds
- Coffee and tea
- MSG (monosodium glutamate), hydrolyzed yeast extract, natural flavoring, hydrolyzed vegetable protein
- Tyramines (wine and aged foods)
- Phenylethylamine (chocolate, garlic, nuts, raw onions, seeds)
- Artificial sweetener
- Citrus fruits
- Pickled foods
With food sensitivities, I believe the best method is to go on an elimination diet for 30 days, then reintroduce foods one at a time. While food sensitivity tests can help, they do not pick up on every food you are sensitive to. Instead of wasting time and money on these tests, it might be better to just remove the most common foods and then add them back one at a time. You need to be conscious about getting adequate nutrition during this time though, because elimination diets are restrictive, making it more difficult to get all of the vitamins and minerals.
Another method would be to keep a food and symptom diary for 30 days and see if there are any patterns between certain foods and headaches. Depending on how sensitive you are, it might only take one food to cause headaches, which makes finding the culprit difficult and frustrating at times.
Histamine and Mast cells
Headaches are a common symptom of histamine intolerance, and persons with migraines are found to have higher levels of histamine. Higher amounts of mast cells in the brain are associated with headaches.
Headaches can be caused by eating high histamine foods, or foods that block the DAO enzyme in persons who have issues with high histamine levels or degrading excess histamine.
However, even healthy persons who ingest too much histamine can get headaches.
Headaches that are caused by histamine are known as a vascular headache, mostly through the release of nitrate monoxide. Nitrate monoxide is released when histamine binds to H1 receptors. (R)
However, histamine can also cause the release of other inflammatory mediators, so it’s likely that there are other mechanisms by which histamine triggers headaches.
A low histamine diet can alleviate headaches. Even if you believe you don’t have symptoms of histamine intolerance or mast cell activation disorder, I recommend lowering your histamine intake to see if it helps.
Tyramine is an amine like histamine that is troublesome for many people. Tyramine can cause vasoconstriction, which increases blood pressure and can lead to headaches. Persons who take monoamine oxidase (MAO) inhibitors have to watch their tyramine intake, because they are not able to break down tyramine as effectively. (R)
I highly recommend persons with headaches, histamine, or mast cell activation disorder read this post, which goes in to more depth about this topic.
The Mastocytosis Society Canada developed a food list that is low in histamine and tyramine, and is worth trying if histamine seems to be an issue. You can download the pdf here.
Hot and Cold Temperature
Headaches can be caused by heat. Heat exhaustion is definitely a cause of headaches, but even a hot shower can cause headaches. (R)
This is especially true if you have mast cell or histamine issues. Not only can heat trigger mast cell degranulation in those susceptible, but heat is also a vasodilator, which can be a contributing factor to headaches in some people.
Some people can also get headaches from cold exposure, but I believe this is less common than heat exposure.
If showers are a cause of headaches, the simple fix here is to take luke warm or cold showers. Not too cold that you get a headache, because it’s too cold, but not hot enough that it triggers a headache. This is easier said than done though, because a hot shower is quite relaxing (until you get a headache). Your body will adjust to a less hot shower, and it’s definitely worth it if it prevents headaches.
Although people can get headaches triggered by both hot and cold, I believe that a lot people tend to get headaches from one or other. If you get headaches from heat, then it is likely that cold will help alleviate symptoms, and vice versa.
Cold therapy (cryotherapy) has been shown to help many people with migraine pain. You can use cold showers, ice packs, or buy a cold pack head wrap. (R)
Caffeine is a cache-22 for not only headaches, but likely overall health in general. It helps some people with headaches, while it may cause headaches for others.
There are couple of plausible mechanisms for why caffeine may be good or bad for you.
Caffeine excites the nervous system, and causes vasoconstriction. Caffeine increases excitatory neurotransmitters by inhibiting adenosine A1 receptors, and causes vasoconstriction by antagonizing A2 receptors in the brain.
Daily caffeine intake could lead to an increase of adenosine and adenosine receptors to compensate for the caffeine inhibiting effects. Adenosine is a strong vasodilator, which is associated with headaches, and therefore, caffeine would now be leading to more headaches instead of helping alleviate them.
Also, people who quit caffeine can have withdrawal and rebound cerebral vasodilation. This is one reason why people have headaches if they don’t have their daily cup of coffee.
Staying away from caffeine for 2 weeks will allow the body to normalize. (R)
I think it’s important to also understand where you are getting your caffeine from. In my case, white tea has a small amount of caffeine, and is not fermented like green or black tea. I can tolerate white tea quite well and don’t seem to have any issues with it. I definitely cannot tolerate regular coffee, it has too much caffeine and causes pre-anaphylactic reactions.
Something else to consider is that most of the caffeine ingested is metabolized by the cytochrome P450 enzyme in the liver, and if you have mutations in this enzyme, it’s possible that you may have a harder time metabolizing caffeine. (R)
Vitamin and Mineral Deficiencies
Low levels of vitamin D is a common issue globally, and low vitamin D is associated with headaches. (R)
Take a look at my article on vitamin D to learn more.
Vitamins and minerals work together, this is super important to understand. Low levels of magnesium are found in persons with headaches, and low magnesium can be caused by vitamin D deficiency. Absorption of dietary magnesium is dependent on vitamin D. (R)
Magnesium supplementation has been shown to help alleviate headaches. (R)
You can read more about magnesium here.
MTHFR and Methylation
MTHFR (5,10-methylenetetrahydrofolate reductase) is an enzyme that regulates folate and methyl groups during methionine synthesis. Long story short with MTHFR, mutations in MTHFR can lead to higher levels of homocysteine, which is associated with increased health risks. Persons with MTHFR mutations such as the C677T variant have been found to have higher levels of homocysteine and suffer from migraines. Deficiencies in folate, B12, and B6 can also increase levels of homocysteine. Vitamins B6, B12, and folate are needed to help metabolize homocysteine and thus decrease migraine pain. Supplementation of these three nutrients have been found to reduce homocysteine levels and reduce headaches. (R)
Riboflavin has been shown to alleviate headaches, and reduced riboflavin activity has been found in persons with headaches. A lot of studies use between 200 and 400 mg of B2, but even a “low” dose of riboflavin (100 mg) has been found to help with headaches. (R) (R)
Bottom line with vitamins and minerals is that you need to make sure you are getting adequate amounts of all of them. However, some people may find benefits from certain nutrients. Be sure to work with a qualified health professional before supplementation.
Exercise can both cause and help alleviate headaches.
Aerobic exercise can reduce the frequency, intensity, and duration of migraines.
Indoor cycling 3 times per week has been shown to be a safe exercise for persons with migraines. (R)
If exercise is a trigger, there a couple of things to try before forgoing all exercise.
Make sure you’re getting ALL of the vitamins and minerals, as well as getting enough calories.
Identify food sensitivities and reduce the amount you eat of them, or cut them out completely.
Start exercise slowly. A short walk is a very good starting point. There’s also yoga, and low impact/low intensity weight training.
Sleep and Circadian Rhythm
Sleep quality is important for health in general, and sleep can often end a migraine. (R)
Poor sleep can mess with many different metabolic processes in the body, including blood glucose regulation, and poor blood glucose regulation can be a trigger for headaches.
You should aim for 7 to 8 ½ hours of sleep.
Medications and Supplements
Certain medications can cause headaches and migraines. Oral contraceptives and vasodilators can increase migraines, (R) but I would imagine that almost any medication could potentially cause a headache as a side effect; depending on the person.
Supplements can also cause headaches. It’s always best to only try one thing at time, that way you’ll know if a supplement or medication is providing benefit, or if it’s causing headaches or other reactions.
Noise is common trigger. (R)
If you’re prone to headaches, avoid loud and “annoying” noises. Earplugs and noise cancelling headphones would be a good idea if you are exposed to headache triggering noise.
There are many ways to reduce stress, you have to find what works for you.
A couple of ways to reduce stress
- stay true to your values
Many people are sensitive to chemicals. There are varying degrees of this disorder, from fairly mild reactions to completely disabling. Headaches are a common reaction to chemicals and scents.
Common products that cause people issues are candles, incense, fragrances, cleaning products, smoke, and soaps. (R)
The best thing to do is avoid these chemicals and scents, and make your home completely fragrance free, or only use specific ones that are safe for you. You can make your own soaps using essential oils, and organic and environmentally friendly products are usually the safest.
Light, Sunlight, and Screen Time
Bright light and sunlight can be headache triggers for some people. Persons with a headache are also often sensitive to bright light. Sunlight may trigger headaches by other means besides seeing the light, such as heat and increased release of nitric oxide when exposed to sunlight. (R) (R)
Too much screen time is also a contributing factor to headaches, which likely has to do with both the light projected by the screen, but also the poor posture that many people have while on their computer or phone. (R) (R)
To help reduce bright lights, one obvious thing to do is where sunglasses if the sunlight triggers a headache. Another thing to do is use blue light blocking applications on your phone and computer at night, which will not only make the light less intense, but it will also help to maintain a healthy circadian rhythm.
I think it’s also important to note that for me in particular, I have found that not having enough light during the day can trigger a headache. For me, I do best with a decent amount of light during the day, and blocking out a lot of blue light at night. I also have to moderate my screen time. If I sense that I am getting too much screen time, I dim the screen and block some of the blue light, which usually helps. If that’s not enough, I shut the screen off and do something else.
In summary, the best thing to do is keep track of when you get headaches. If you have daily headaches, then it will likely require more drastic lifestyle changes in order to determine what's causing them. I believe that maintaining healthy blood sugar levels, getting adequate nutrition, eliminating or decreasing food sensitivities, reducing physical, chemical, and emotional stress, finding the right type of exercise, getting adequate sun and keeping a healthy circadian rhythm will help alleviate headaches for most people.
As always, check with your doctor or other qualified health professional before trying supplements.