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.

< Previous Article
Metabolic Syndrome
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!

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

  1. Cheska February 8, 2016 at 11:58 am - Reply

    So I get headaches when I eat to much sugar. But I also see stuff at the corner of my eye. And I am not sure if I have diabetes or not.

    • Dr. Scott February 8, 2016 at 1:43 pm - Reply


      Diabetes does effect eyes, but the changes usually happen slowly over time. I would check with an eye doctor about the eye problem – I’m not sure it is sugar related. If you think you have diabetes, I would suggest seeing your doctor.

      Dr. Scott

  2. Lynn February 4, 2016 at 6:52 am - Reply

    If I eat sugar after 7PM I will wake up with a horrible headache. It can be as early as 4AM. It can be sherbert, plain applesauce, cookies or candy. It doesn’t bother me any other time during the day. What could be the cause of this?

    • Dr. Scott February 6, 2016 at 9:45 am - Reply


      Sugar tends to create inflammation in the body and the brain is very sensitive to a lot of things that come along with sugar (preservatives, coloring, even grains). This makes for a painful morning for a lot of people who eat sugar. Your best bet is to try and remove sugar and the foods that act like sugar for a while (like the 30 Day Program) and see how it goes.

      Dr. Scott

  3. Margaret January 1, 2016 at 6:22 pm - Reply

    I have been having headaches almost every time I eat sugar – unless I have just eaten a meal. Anything with sugar – cookie, chocolate, hot chocolate, anything – gives me a headache almost as soon as I swallow it! My sister was diagnosed with hyperglycemia when she was 19 – she is now almost 50 and has lived for 30 years with NO sugar! And no more problems with headaches or body shakes. I just turned 40 – could I possibly be hyperglycemic also? After such a long time of having no problems with sugar? Could I have brought this on myself when I went on a sugar-free diet for about 6 weeks and then re-introduced sugar?


    • Dr. Scott January 2, 2016 at 9:17 am - Reply

      Margaret, problems with sugar (including diabetes) runs in families. Typically, people get worse at controlling blood sugar as they get older – so, yes you can see this after having no problems for many years. It is unlikely that you 6 week, sugar-free diet had anything to do with your problem. It appears that you, like your sister, are very sensitive to sugar and should work to remove it from your diet as much as possible.

      Dr. Scott

  4. Nat December 27, 2015 at 4:57 am - Reply

    After giving up ALL sugar for 9 weeks (inc. all fruit) I had some homemade mince pies (dried fruit, paleo) freshly squeezed orange juice and a Xmas pudding (dried fruit homemade and paleo) this Xmas I have been sick ever since! Intense headaches, coldsores and sore throat? Bizarre that natural fruit can do this after just 60 days off!?!?! ???

    • Dr. Scott December 27, 2015 at 4:04 pm - Reply

      Hi Nat. It is amazing how it doesn’t matter the source of the sugar (natural or not); it can still affect you.

      Dr. Scott

Leave A Response