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.


  1. My entire family has heen battling an extreme shift in our health over the last 3 years…including newly developed sugar hangovers that include sinus pain, headaches, next-day fatigue, brain fog, and joint aches. We are all of normal weight and after hundreds of hours of reading and research, I have finally narrowed it down to what I think are failing tight junctions in our digestive systems caused by GMOs we’ve been consuming for the last 10 years. Specifically, the use of a soil bacteria (Bt) in seed engineering to produce corn that can’t be killed when sprayed with Roundup which contains glyphosate. Additionally, Bt produces a toxin in the corn that dissolves the lining of the nsects that eat it. The introduction of Bt into our gut via the food we eat coupled with the RoundUp that has been absorped by those same crops is a double-whammy to our gut biome: Bt shifts the bacterial make-up and is wearing down the protective barriers that regulate what is and is not allowed in our bloodstreams. There are multiple studies that show a dramatic uptick in immune responses in farm workers who are exposed to Bt Toxin. Even Russia has banned Bt corn. Why hasn’t the US?

    1. Dawn,

      I couldn’t have said it better. Roundup residues in our foods completely destroy our micobiome (and, along with it, our health). Roundup was originally patented as an antibiotic (then as a de-greaser). Farmers are going to continue to use it (1) because it means they need less workers (to manually weed) and (2) because it dramatically increases yields (when sprayed near the end of the plants life cycle). Removing sugar and foods that act like sugar goes a long way to reducing exposure to glyphosate (but does not eliminate it). Sugar and foods that act like sugar also directly increase headaches.

      Thanks for your input!

      Dr. Scott

  2. I get head aches after drinking a regular coke I have drink diet since I was 10 after my headaches I get lightheaded and dizzy I lose my hearing and feel like I’m going to pass out about 30 mins or so it passes but I’m weak I actually had a glucose test with me the last time and my result was it bottom out to 50 I don’t understand

  3. Hallo,
    I have headaches whenever I eat sugar. It lasts for two days or more. It’s been around two years since it first started.I have pain around the sinus organs so I took an X-Ray but it turned out normal. I even had a blood test and that’s normal as well. What can I do now? Thesedays I have swollen neck as well. Swollen in the sense it pains if I touch. I am taking anti biotic but the pain is still there. What’s wrong with me? Any idea?

    1. Hi Dechen,

      It is impossible to make a diagnosis over the internet. It sounds like you need to make an appointment with your local doctor to help you health concerns.

      Dr. Scott

      1. Well I consulted my local doctor but it seemed like he was shocked to hear that sugar can cause sinus pains.

        1. Happens to me all the time.
          I haven’t eaten sugar for years, but when I do I get a raging ‘sinus’ headache.
          I am convinced it is inflammation caused by the sugar.
          This happens to me when the weather changes quickly as well.
          Wish i could fix it somehow. I take way too many ibuprofen

    2. The same thing happens to me. I went off processed sugar for a couple of weeks eating only natural sugars in fruits and the two times during that 2 week period I ate a cookie and within the hour my head was killing me and it felt just like a sinus headache.

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