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!

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

  1. Chris February 12, 2015 at 3:42 pm - Reply

    I took the medication Levaquin, which I’m apparently allergic to. Aside from neuropathy and wide-spread pain, I’ve had headaches whenever I eat something with sweetness. I’m concerned that I might have diabetes (my last blood test indicated 99 out of 100). I wonder if a non-fasting blood test would be best.

    Also, I wonder if the Levaquin could have caused a “Leaky Gut” situation.

    Thank you. Chris

    • Dr. Scott February 13, 2015 at 7:40 am - Reply


      Yes, it is possible that levaquin has caused leaky gut. You are on what I consider borderline for diabetes (doctors use 110). Try a program of staying away from sugars and see how you feel. Your gut can heal if you stay away from foods you might be allergic to and take a good probiotic.

      Best of luck.

      Dr. Scott

  2. Mary January 12, 2015 at 11:05 pm - Reply

    Great article. I kept a head ache log to track what I ate for a year or so and finally stumbled upon relief from my head aches once I cut out sugar and processed grains. My head aches would last 2 or 3 days and this went on for several years.
    I also discovered that histamines in certain grains and foods were causing me to have sinus issues too. I no longer have to use a nose spray prescribed to me or take a decongestant now that I stopped eating sugar, processed goods, bread (except for sour dough or gluten free) and cut back on dairy.

    • Dr. Scott January 14, 2015 at 9:14 am - Reply


      Sounds like you are doing great and discovered the triggers present in many foods (especially sugars and grains).

      Dr. Scott

  3. Norm January 2, 2015 at 12:38 pm - Reply

    I get a small headache on the right side of my head between my right ear and temple. I can pinpoint it right to sugar. No Sugar no headache. When I eat to much sugar I can’t lay on the right side of my head. I am 72 years of age and diabetise is in my family, so I have to be careful, Begin 72 you get all kinds of things happening to your body. I also have ringing in my ears, blurred vision, dizzy spells ect,ect. The list is never ending. Most of the time I feel great but right now I need a nap.

  4. Crystal January 1, 2015 at 12:06 am - Reply

    I have always had headaches for a long time. I have been on a sugarfree no carb diet for 3 months. I ate sugar cookies (Not many) today and bam my headache is back so bad that i Googled it and found this site. I feel like the first persons comment about mussels tensed and hands having stiffness is what aI feel. I am wondering if glutin or grains have part in this also. I have not been eatting them too. I think I am going to try one of something a day until I can pin point it. Thank you for this site.

    • Dr. Scott January 1, 2015 at 6:58 am - Reply


      Yes, grains can be a big part of this (they often act like sugar in your body). You have it exactly right: your best plan is to try one a day and see what happens (we all have different sensitivities).

      Dr. Scott

    • Demian January 4, 2015 at 10:22 pm - Reply

      Crystal, my sister had really bad migraines for several years…. They finally found out that she has celiacs. Sounds like it is Glutin in your diet that may be causing the problem, however I’m no expert. You should check with your doctor.

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