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 strikes any time we are ditching phentermine for keto and 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.

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!

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

  1. Rajesh Goyal September 18, 2014 at 8:47 pm - Reply

    I have headache only next day morning I eat cake or sweets, It ends by the evening. No painkiller affects and it automatically goes. I never goes for too many time for urinals, drinks normal amount of water. I got my tests done for diabetes but comes normal. I have a feeling of thirsty in my mouth, my tongue and inside cheeks feels thirsty. Is this a pre diabetic stage? If I don’t eat sweets I don’t have headache…

    • Dr. Scott September 19, 2014 at 2:02 pm - Reply


      Yes, this sounds much like pre-diabetes. Sounds like it would be good for you to stay away from sugar.

      Best of luck,

      Dr. Scott

  2. CPoynter September 16, 2014 at 9:20 am - Reply

    I often get sugar head aches that are different than most. I get blurred vision and slight pressure at the sides and top of my head and have yet to find anything that will relieve it quickly. Pain relievers don’t work, and I’ve even tried drinking water (thinking that it would flush the sugar from my system) but it doesn’t help either. I know a lifestyle change is the ultimate fix, but any suggestions for a quick one?

    • Dr. Scott September 16, 2014 at 12:54 pm - Reply

      Sorry, no quick fix for that, avoiding sugar is the only way I know to avoid those headaches.

      Best of luck!

      Dr. Scott

  3. Tasha Lee September 15, 2014 at 10:05 am - Reply

    Thanks, this was interesting. I am a type 1 diabetic & fruitarian raw foodist. Yesterday I bought a few different packs of dried fruit and mixed them together as a sort of trail mix. Today I have a strange headache in the front of my head. I was guessing dehydration, but then started wondering if it was the preservatives or something. I read on the various packages, “sugar”,”sulfur dioxide”, “artificial flavor”, etc. I enjoyed reading about the correlation and different possibilities for what could be the cause of my headache. I understand that the cleaner my body gets, the more sensitive I will continue to become. I appreciate you speaking bluntly about this sort of “not typical doctor’s advice”! :) Blessings.

    • Dr. Scott September 16, 2014 at 6:54 am - Reply

      Hi Tasha,

      Ultimately it is hard to link what you are eating to headaches unless you experiment a few times. Yes, sulfur and artificial flavors could be the cause, but so can sugar. Many people find that fructose (fruit sugar) is much worse than glucose or other sugars. Thanks for your comments and good luck on your journey to health.

      Dr. Scott

  4. Katie August 20, 2014 at 7:41 pm - Reply

    I just finished a 21 day cleanse of all organize fruits veggies and meat on the standard process cleanse. I ate a small cookie this after and had one of the worst headaches ever. I never had a sugar headache ever before. Would this be related?

    • Dr. Scott August 21, 2014 at 5:08 pm - Reply


      It is amazing what happens when you clean up your diet. Often you become more aware of what you are sensitive too. The sugar is a possibility, but cookies also contain a lot of other ingredients (grains? artificial sweeteners? colors? preservatives?) that can also be triggers for headaches.

      Dr. Scott

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