Why Does Sugar Give Me a Headache?

Why Does Sugar Give Me a Headache?

Does eating sugar give you a headache? You are not alone.

The sugar headache, otherwise known as the Holiday Headache (because we eat so much sugar on Easter, Halloween, Christmas and other holidays) has a lot in common with a hangover but it can strike at any time we overdose on sugar.


While most of us have experienced a sugar headache at some time in their lives it is not well-known in medical circles. It might even surprise you to learn that the exact causes of all headaches are a bit of a mystery. Scientists have discovered that both migraines and cluster headaches change blood flow in the brain,  but exactly how blood flow changes create a headache is unknown. The same is true of the sugar headache.

I view the sugar headache as a toxicity or dehydration event and while it might be an annoyance, it could also be the sign of something more dangerous. Let’s look at dehydration and toxicity and see how they might cause a headache.

Sugar Dehydration

Dehydration is a common way to get a headache and sugar can lead to dehydration. Eating too much sugar pulls water out of your body in two ways.

  • Dilution: When you eat too much sugar, your body has to dilute that sugar to keep it from harming your body. This means that water is pulled from all parts of your body to balance the large amount of sugar in your blood stream. While this water-pulling effect happens all over the body, it is your head that suffers the most.
  • Urination: One of the ways that your body has of getting rid of excess sugar is to dump it in your urine. This is especially true of diabetics, who have to go to the bathroom a lot.


The other way to think about sugar is to consider it a toxic event.

While your body runs on glucose (a simple sugar) it was never meant to have a ton of simple sugars running around in your blood. If you look to nature, you would find that there are almost no foods that contain the high amount of sugar you would find in any soda or piece of cake. If natural foods do contain a high amount of sugar it is often bound up and hard to get to (like in a sugar cane). The only way to get a large amount of sugar into your body is to have that sugar processed before you put it in your mouth.

Processed sugar and processed grains both act like sugar in your body and this is toxic to the very blood cells that carry the sugar throughout the body. (I explain this at length in my book Sugarettes).

Something Worse?

Sugar headaches can also be a warning. If you get sugar headaches often, you might just be diabetic or pre-diabetic. The best way to find out if you are diabetic is to go and see your doctor and have them run some blood tests, but here are the typical symptoms of diabetes:

  • Excessive urination: As I mentioned above, sugar acts like a diuretic and will spill sugar and water into the urine. Having to urinate a lot is often one of the first signs of diabetes.
  • Excessive thirst: Since diabetics are losing a lot of water (see above), they are often thirsty all the time.
  • Excessive hunger: Everyone has periods of time when they are hungry, but diabetics are hungry all the time (with strong cravings for carbohydrates, sweets and sugar). This is one of the strange things about diabetics: They have a lot of sugar in their bodies, but it is not being used by the cells so they are hungry all the time.

Sugar Headache

The reasons why sugar gives you a headache are many and not readily understood, but you don’t have to wait for a reason to stop the pain in your head.

You can stop your sugar headaches and give sugar the boot by trying my 30 Sugar Free Days Program. During the program, you will learn about foods that act like sugar and what you can do about your cravings. Make sure you understand that sugar is doing more harm to your body than just giving you a sugar headache, take this opportunity to learn from your headache that you shouldn’t be putting large amounts of sugar in your mouth and you need to make a change.

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About the Author

I'm Dr. Scott Olson ND. I'm a Naturopathic doctor who specializes in diet, health, nutrition, and alternative medicine. I've written numerous books and articles on health, medicine, and alternative medicine I want to help you get healthy! Take a look at my blog and make sure you join in the conversation!

205 Comments on this article. Feel free to join this conversation.

  1. Lakreshia Gadiso November 8, 2015 at 7:35 pm - Reply

    I have been getting headache from energy drink even nature ones for long time I stop taking them now . However, I love candy and I use to eat it a lot with no headache.Now I starting to get headache from eating sugarer candy.
    What happen nothing change in the candy .

    • Dr. Scott November 9, 2015 at 10:46 am - Reply


      It sounds like you are getting more sensitive. It happens to a lot of people. I think it is a good thing to kick the sugar out of your life.

      Dr. Scott

  2. mary November 4, 2015 at 8:33 am - Reply

    question … found your sight while searching for my 11 yr old daughter … after 4 yrs of watching same pattern… she is ADHD / Border Baby … adopted age 2 always been in 5th to 10th bw ptile
    her bday is 11/1 so you can image desire to trick or treat then celebrate bday w sugar … but usually only after a handlful of candy she is vomiting… i am almost sure sugar intolerance as i see typical hypoglycemic response, other wise she is very cautious and does not eat alot of sweets, or carbs other than pasta couple times of month … some have said gluten but we barely eat wheat products… she loves fruits and veggies
    should i have her tested for sugar issues or just continue to manage diet … symptoms are ha then nausea then vomiting x1-2 then fine again

    • Dr. Scott November 5, 2015 at 7:10 am - Reply

      Mary, you can have her tested, but what you are doing (paying attention) is just a reliable. The more you can move your daughter away from processed foods to whole foods, the better.

      Dr. Scott

  3. Elisa Musolino November 2, 2015 at 7:45 am - Reply

    I stopped eating everything that contained sugar and refined carbohydrates and only have a little bit of fruit a day eg: one slice of rockmelon or 1/4 cup of blueberries or 1/2 a banana… And I went from headaches every week plus at least one migraine a month to nothing not one headache or migraine ever again plus I’m soooo much more energetic, clear headed and happier

    • Dr. Scott November 5, 2015 at 7:01 am - Reply

      Elisa, sounds like you are doing great!

      Dr. Scott

  4. Lisa October 31, 2015 at 11:23 pm - Reply

    We have a 4.5 year old son who is getting headaches about twice a week. Thinking sugar or food additives does it for him. Could the sugar in homemade jelly cause a headache? He eats PB&J sandwiches 3 times a week at school. He has vomited and always has to sleep right after he gets meds. It’s affecting his and our lives and trying to find a cause is frustrating!

    • Dr. Scott November 2, 2015 at 6:05 am - Reply

      Lisa, yes homemade jelly could cause the headaches. Have you thought about looking into the foods that act like sugar (such as wheat?).

      Dr. Scott

  5. Lori October 18, 2015 at 4:29 pm - Reply

    My daughter has recently been diagnosed with IBS-C. They’ve done endoscopy, colonoscopy (both with biopsies), checked bacterial levels, and had her swallow a camera pill. Part of the testing also included two tests for Celiac, which were negative. I really expected the Celiac diagnosis largely because of the foods she was eating before some of her worst bouts of headache and stomach pain. However, I’m thinking more and more that it’s sugar specifically, not gluten. For instance, she ate a cookie the other night and spent the night in bed, fetal position, crying with stomach cramps and a migraine. Can a sugar intolerance be that severe and that instantaneous? She’s 17, so she’s been paying attention and seems to think sweets are the trigger. She used to love Milano cookies and hoard the bag to herself any time I bought them. Now she might eat one or two in a sitting, but typically feels so poorly afterwards, she passes the bag along to someone else. She might come back a week or two later and ask if there are any left, but even that’s rare these days. She does say though that some potato chips bother her. She had some sort of plain wavy chip and said that hurt, but SunChips did not. Just not sure what else could be causing such severe headaches and stomach pains so instantly and so severely.

    • Dr. Scott October 19, 2015 at 1:25 pm - Reply


      Yes, sugar and foods that act like sugar can be the source of headaches/IBS. While it is a difficult journey with someone who is your daughter’s age, working with her to eat only fresh (non-processed) foods is a good place to start. Try having her only eat proteins and vegetables for a week and see what it does for her symptoms, then she can try testing different foods to see if they are the source.

      Good luck,

      Dr. Scott

    • caroline mcritchie October 19, 2015 at 3:50 pm - Reply

      I have just self-diagnosed my headaches to sugar. Doesn’t matter what kind even a teaspoon of Jelly will give me a severe very localized headache approx 20 minutes after I injest the sugar. I’m trying to go sugar free for a week & validate what I feel. Breads/Carbs don’t seem to tip it off. It used to be a major midnite migraine if I ate 3 or 4 chocolate chip cookies with vomiting. Now it’s not a migraine but possibly a cluster headache. I do crave the sweet tastes but will remember my summer time solution to the sweets – fruits like peaches. However grapes that taste really sweet are also a culprit. Good Luck with a solution.

      • Dr. Scott October 20, 2015 at 6:19 am - Reply

        Hi Caroline, it sounds like you may have a sensitivity to fructose (table sugar is 1/2 fructose), but be on the lookout for those foods that act like sugars (even though you say breads don’t cause your symptoms).

        Dr. Scott

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