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 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!

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

  1. nettie bradley August 11, 2014 at 1:28 pm - Reply

    I too get head aches after eating some sweets. I also need new glasses. Im going to my doctor on wed, i will let her know about this. Do you have any advice.

    • Dr. Scott August 13, 2014 at 8:20 am - Reply

      The best way to determine whether your headaches are from sugar is to remove it for a week or two and then test it again. If you are worried about your blood sugar control, then ask your doctor for a blood test. Yes, headaches can come from needed glasses.

      Dr. Scott

  2. Deborah August 5, 2014 at 10:37 am - Reply

    Not sure what causes this, but when I ave to urinate and while urinating, I get a really bad head ache. Can you help me with the answer to this problem?

    • Dr. Scott August 5, 2014 at 10:54 am - Reply


      There can be many reasons for this and I would suggest a trip to your doctor for some tests. Most people who experience this have a rise in blood pressure following urination. You can check this for yourself by taking your blood pressure both before and after you urinate, but seeing a doctor is your best bet.

      Dr. Scott

  3. Sydney August 5, 2014 at 12:43 am - Reply

    I find that every time I eat something sugary, I get a headache. I’ve had mild migraines since I was a young child. But I also cracked my skull when I was a little toddler. The spot on my head is very sensitive to this day and when I get a headache, this spot aches the most. Is it the sugar or what?

    • Dr. Scott August 5, 2014 at 10:52 am - Reply

      As you can tell from the comments left here, many people get headaches when they consume sugar. It is hard to say whether this is true for you or not. The best way to discover this is to remove sugar from your diet for a while and then reintroduce it.

      Dr. Scott

    • michael August 5, 2014 at 11:12 am - Reply

      I never had a problem with headaches before. Until, I had a major accident with my quad runner. Ever since, nighttime Cluster Headaches and found after stopping diet pop, sugar gives me a head pain. Not the CH level. More me, no doubt the prior head injury was the key.

      Take Care,


  4. michael August 2, 2014 at 10:40 am - Reply

    I’ve had Cluster Headaches for 5 after an accident. I drank my share of diet pop thinking it would help keep the my waist line in check. I found my diet drinks were liquid poison.

    I make the switch to regular sugar, regular pop sugar etc. Found I was having bad headaches each and every time afterward. Not Cluster Headache, still pretty bad.

    I’ll be backing off both..



    • Dr. Scott August 3, 2014 at 11:46 am - Reply


      Yes, both artificial sweeteners and sugar can cause headaches. Let us know how it goes when you stop them.

      Dr. Scott

  5. Tierra July 15, 2014 at 11:35 am - Reply

    I’ve been drinking a lot of koolaid lately which is very sugary and now everytime i drink it or something i get a slight head ache everyday.

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