Though headaches are not a common symptom of diabetes, they’re a frequent topic of discussion on DiabetesTeam. One member noted how their headaches can disrupt their entire day: “I hate waking up and having a severe headache all day. I can’t take ibuprofen, just Tylenol. It doesn’t help.”

Another explained that their headaches disappear quickly: “I had a headache again this morning. They don’t last long once I get up.”

Meanwhile, one simply observed, “What’s up with everyone having these headaches?”

Frequent headaches can be frustrating, especially if you don’t know why they’re happening. Here are some possible causes of headache in people with diabetes.

Causes of Headaches in People With Diabetes

In people with diabetes who experience headaches, the frequency, severity, and length can vary depending on the cause. Head pain caused by diabetes mellitus (or another condition) is referred to as a secondary headache, while primary headaches aren’t due to other medical conditions.

If you’re living with diabetes, here are some reasons you may be experiencing headaches.

High Blood Sugar Levels

One possible cause of headaches is hyperglycemia (high blood glucose, or blood sugar). If you have diabetes, you may experience high blood glucose levels often. One of the first symptoms you may notice is headache.

Blood sugar headaches are due to increased pressure in the blood vessels of the brain as they respond to hormones. Other signs of high blood sugar may include:

• Increased hunger or thirst
• Peeing more often than usual
• Blurred vision

In type 2 diabetes, high blood sugar is generally defined as blood glucose higher than 180 milligrams per deciliter (mg/dL) one to two hours after eating. However, what’s considered high for you depends on your target range. In people with other types of diabetes, such as type 1 diabetes, high blood sugar is defined differently.

In diabetes, high blood sugar levels can occur if:

• You don’t take enough insulin
• The amount of insulin isn’t balanced with your carbohydrate intake
• You don’t time your insulin and carbs right
• You reduce your physical activity level
• Your diabetes medicine dose is too low
• Your body’s hormones naturally raise your blood sugar early in the morning — called the Dawn phenomenon

If your headache is due to hyperglycemia, it may become more severe without blood sugar management. Over time, high blood sugar levels can also lead to other complications, such as heart disease and stroke. Proper diabetes management, including blood sugar monitoring, can help to prevent complications.

Low Blood Sugar Levels

“I also get a headache when my blood glucose goes low. Check your numbers. Treat if necessary,” said one DiabetesTeam member.

Hypoglycemia (low blood glucose) is another potential cause of headaches for people living with diabetes. Low blood glucose levels can be due to:

• Taking too much insulin or other medication that lowers blood sugar
• Eating too little after taking diabetes medication
• Increasing physical activity
• Drinking alcohol (especially liquor)

Headache is one of several symptoms of low blood sugar. Additionally, research has shown a connection between low blood sugar levels and migraine attack. Low blood sugar may cause or worsen migraine attacks. Fasting (skipping meals) was reported as a headache trigger in 39 percent to 66 percent of people with migraine attacks.

Other signs of a hypoglycemic episode may include:

• Shakiness, paleness, and sweating
• Lightheadedness or dizziness
• Fatigue
• Irregular heartbeat
• Nausea or hunger
• Difficulty focusing

Glucose provides the main fuel for your body, so it’s important to raise low blood sugar promptly. If blood sugar remains low, symptoms may get worse. You may begin to experience blurry vision, confusion, or slurred speech. One member noted, “By the end of the day in the evening, I get tired, and my vision gets very blurred, and when I wake up in the morning, I have a headache.”

If you experience many low blood sugar episodes, your body may stop showing warning symptoms. Without symptoms to alert you of low blood sugar, your risk for life-threatening hypoglycemia increases.

Dehydration

When someone has diabetes, they may drink more and go to the bathroom more often. That’s because their kidneys can’t keep all the sugar in their blood, so it leaves the body through urine. This also pulls water from the body, causing dehydration. Dehydration can lead to headaches and makes some last longer.

If your headache is due to dehydration, you may feel pain broadly through the whole head or in just the front or back. Head pain can also be limited to one side, but that’s less common. Certain head movements, such as leaning your head forward, often make the pain worse.

If you have a headache from dehydration, drinking water should help. Try drinking at least 16 ounces to 32 ounces of water. This should ease the pain in one to two hours. Headaches from more severe dehydration may last several hours and require you to drink more water.

One member shared, “I get really intense headaches when I’m getting dehydrated. I don’t feel thirsty, but apparently, my body is, so I drink water throughout the day and especially before bed. … Yeah, late-night bathroom trips. My endo suggested Powerade Zero to add electrolytes, and that was the ticket for me. Headaches gone in about 10 to 15 minutes!”

Another wrote, “I really never knew why I got the headaches, but that makes a lot of sense ’cause I drink water and it seems to calm it down.”

Other Causes of Headaches

People with diabetes may also experience headaches that aren’t caused by their diabetes. Allergies, for example, have been shown to trigger both migraine attacks and sinus headaches. Migraine headache is usually limited to one side and can feel like a throbbing pain. Sinus headache pain may be felt near the sinuses — in the forehead, cheekbones, eyes, and bridge of the nose — and tends to be most intense when you’re lying flat.

“Mowed the lawn yesterday, so that may account for the headache. Allergies. Lots of goldenrod in my backyard,” one member wrote.

Another said, “I never hated allergies more than now. Not a lot we can use for them. I get headaches too from the lawn being mowed.”

Make sure to check your blood pressure as well. Elevated blood pressure can cause headaches. If your blood pressure is constantly high, you need to talk to your doctor.

Headaches can also be caused by vision problems. If you are not wearing your glasses (or you noticed you stopped seeing well with them), you need to get another optometry reading. However, fluctuations in blood sugar levels can cause the natural lens in the eye to swell, leading to blurred vision and changes in prescription. Make sure your diabetes is stabilized before getting a new prescription.

Head pain can also come from tension headaches — pain caused by tightening of head and neck muscles. Common causes of tension headaches include:

• Poor sleep
• Stress
• Hunger
• Fatigue
• Consumption of alcohol, chocolate, or other trigger foods or drinks
• Weather changes
• Medication or caffeine withdrawal

Treating Headaches With Diabetes

If you’re experiencing headaches with diabetes, you may not know where to start when it comes to treatment. “This morning, I had a headache again, this time blood glucose was 107. I am trying to figure out what to do about my headaches. Any suggestions?” a DiabetesTeam member asked.

Another questioned, “How do I get rid of headaches, especially in the morning?”

While headaches from dehydration can be remedied by drinking water, it’s important to make sure there isn’t another cause of your headaches, like low or high blood sugar levels. If you have diabetes, it’s important to check your blood sugar when you have head pain. Treat high or low blood sugar levels promptly, and follow your diabetes care plan as your doctor prescribed.

Over-the-counter (OTC) pain relievers, such as acetaminophen or ibuprofen, may help treat lingering pain. Talk with your healthcare provider if you experience headaches regularly, especially if they’re severe.

Talk to Your Doctor

Though blood sugar fluctuations have been linked to headaches, overall, there’s limited research on headaches in diabetes. It may be helpful to track when you get headaches and how severe they are. Knowing if there’s any pattern to your headaches can help your doctor create a treatment plan for you. Keep a record of your headache symptoms to refer to so that it’s easier to discuss details you may otherwise forget when seeking medical advice.

Talk With Others Who Understand

DiabetesTeam is the online social network for people with diabetes and their loved ones. On DiabetesTeam, members come together to ask questions, give advice, and share their stories with others who understand life with diabetes.

Have you experienced headaches due to diabetes? Have you noticed specific headache triggers? Do you have any tips for managing headaches? Share your thoughts in the comments below, or start a conversation by posting on your Activities page.