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!

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

  1. Gary June 16, 2015 at 6:15 pm - Reply

    I’ve had daily quite severe neck pain for years.
    I’ve been checked for most everything, diabetes, had 3 MRI’s, acupuncture, laser treatment, etc. — Mild arthritis is all they could see. I exercise regularly.

    I read a book called ‘Wheat Belly” (I’m not over weight) and got sugar out of my life including wheat which converts to sugar.
    That made a huge improvement.
    I had 5 strawberries today and am suffering again.

    • Dr. Scott June 18, 2015 at 7:41 am - Reply

      Sorry to hear about your pain. It sounds like you are open to dietary changes, let me suggest you check out the book “The Paleo Approach”. It talks about inflammation and how foods effect diseases such as arthritis.

      Dr. Scott

  2. Sidonia June 15, 2015 at 3:15 pm - Reply

    Hi every time I eat a mini chocolate bar I would get a headache and feel tired..what could be the cause of this problem?

    • Dr. Scott June 18, 2015 at 7:27 am - Reply

      Hi Sidonia,

      There are many ingredients in a chocolate bar that might cause this, but sugar is certainly one of them.

      Dr. Scott

    • amie June 18, 2015 at 9:12 am - Reply

      Absolutely! This is exactly what I experience. It is rare now that dealing with the symptoms of eating sugary foods is worth it, great job tuning into yourbodys signals!

  3. Alshamget June 14, 2015 at 5:55 pm - Reply

    I have a serious headache almost every day. The pain is getting worse and worse from day to day. Mostly the pain starts after taking sweets. I feel like the pain has something to do with my teeth. Because the pressure is high on my jaws especially on the right side. My family has diabetics problem. But my doctors checked my blood sugar many times and said its normal. I am suffering a lot. Please give me your advise.
    PS: For your information I have high blood pressure and taking Enalapril.

    • Dr. Scott June 15, 2015 at 8:04 am - Reply


      There is no doubt that a sugar-free diet can help you and would be a good idea given your family history. You might also want your doctor to look and see if you have sinus infection (these sometimes present as upper teeth pain).

      Dr. Scott

  4. Michelle Natashima June 9, 2015 at 11:00 pm - Reply

    I am in process of cutting sugars and starchy foods as well as junk food, but when I have a little snack as a reward, in get a headache or nauseous. Could it be a mental thing I am doing to myself or for real? Should I go get tested for diabetes?

    • Dr. Scott June 10, 2015 at 5:02 am - Reply

      Hi Michelle,

      Actually, what you are experiencing is very common (check out the comments on the 30 Sugar Free Days Program, or the Facebook page for the program). As far as getting tested for diabetes, it is very easy to do and a good idea if you have anyone in your family with the disease or are worried about whether you might have a blood sugar problem.

      Dr. Scott

  5. G Buchanan May 16, 2015 at 2:34 pm - Reply

    I have reactive hypoglycemia, and I suffer their excruciating pain that nothing else has ever equaled.
    I know my low blood sugar can be well-controlled with a high-protein, low-carb, no sugar diet but it’s expensive and I fall short of perfect adherence to my proper diet. And then I suffer dreadfully. It could be the death of me some day,

    • Dr. Scott May 21, 2015 at 7:49 am - Reply

      High protein diets can be expensive, but you can also focus mostly on low sugar vegetables (greens…) and still feel full (with a little added protein).

      Dr. Scott

      • Nancy Mills, PA-Midwife June 8, 2015 at 1:33 pm - Reply

        Dear Scott, There is a book called “No More Headaches No More Migraines” Having read most everything this book by Zuzana Bic, DrPH is the best info I’ve seen.They did a study through Loma Linda University which had some good results.They say high fat, high sugar is the problem and they discuss the whole chemical reaction. It’s helped me solve some of my headache problems.
        Nancy Mills, PA-Midwife

        • Dr. Scott June 10, 2015 at 4:57 am - Reply

          Nancy, thanks for your comment. I’ll take a look at the book.

          Dr. Scott

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