Medically reviewed on October 19, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Sometimes, your headache might simply result from stress related to the deadlines and to-do lists on your plate. However, repeated headaches after eating may be a sign of a separate condition—high blood sugar.
Blood sugar is an important factor in your health. The blood carries glucose, or sugar, throughout the body to give you energy. But if blood sugar is too low or too high, you can suffer from related health symptoms, including headaches. So, can stress raise blood sugar? High stress levels can affect how the body regulates glucose and increase the levels.
If you suspect headaches are a symptom of blood sugar issues, it’s important to understand how they are related—and whether your high or low blood sugar levels could be linked to another health issue, like type 1 or type 2 diabetes.
Before diving into headaches and abnormal blood sugar levels, it’s important to understand what blood sugar means.
Your blood sugar measures the amount of glucose present in the bloodstream. This sugar molecule is the body’s main source of energy, fueling every single organ and cell in the body. And to get this fuel, you need to eat.
Every glucose molecule you receive comes straight from diet or from stored energy. To turn food into energy, your body processes blood sugar through these steps:
In a healthy person, blood sugar hovers between 70 to 140 mg/dL, usually staying below 99 mg/dL when fasting. However, certain health conditions can push blood sugar outside of this window—particularly diabetes.
Diabetes is a metabolic condition in which your body fails to make enough insulin or has less sensitivity to insulin release. As a result, the body can become hyperglycemic, the medical term for high blood sugar (and levels can rise up to 180 mg/deciliters or higher). 
While all diabetics are susceptible to hyperglycemia, the cause of this issue differs between each type:
Think of blood glucose levels as a scale. Go too low or too high, and your entire body is thrown off balance—and the first warning sign just might be a headache.
Headaches are a very common symptom among adults. In fact, almost half the adult population has at least one headache per year.  Medically, headaches can be broken down into two types:
Hyperglycemia is a cause of secondary headaches. When blood sugar levels rapidly rise, they can create headache pain via:
For many hyperglycemia sufferers, a headache is the first symptom to appear. However, high blood sugar doesn’t always create symptoms, even at higher levels above 180 mg/dL.  It can take days or weeks of chronic high blood sugar levels to develop hyperglycemia symptoms.
When dealing with high blood sugar, the key is to pay attention to your symptoms and act quickly. The longer you suffer from hyperglycemia, the more likely you’ll develop serious symptoms.  Continuous high blood sugar issues may also indicate that you have or are at risk of developing type 2 diabetes.
Chronic post-meal headaches are usually the first sign of hyperglycemia. However, you should also keep watch for other signs that your blood sugar remains too high, such as:
Curious if that headache is just a result of some tension—or something more? Our team can help you find out. If you suspect diabetes or metabolic conditions might affect your health, the Everlywell At-Home HbA1c Test can lend a guiding hand.
By learning about the prediabetic range of HbA1c levels and measuring HbA1c levels, our test evaluates your blood sugar levels over the past three months. This marker gives a more effective evaluation of your health than a singular blood glucose level measurement, pointing to any long-term metabolic issues.
If you’re ready to protect your metabolic health, learn more about our HbA1c at-home test today.