Diabetes and headaches: What’s causing the pain?

Not all headaches will be related to Type 2 diabetes, but some may be. Learn more about how you can manage diabetes headaches.

February, 2021


There are lots of things that can cause you to have a headache. These can range from colds and fevers to being caused through an injury to the head. They’re one of the most common health issues we all experience one time or another.

A headache may sometimes be linked to a long-term condition. In diabetes, they might be a sign of low blood sugar levels (hypoglycemia). In some cases, a headache might be a symptom of a serious complication caused by high blood sugar levels (hyperglycemia).

By doing all you can to keep blood glucose levels within normal ranges, you will help to avoid diabetes-related headaches.

Are headaches a symptom of Type 2 diabetes?

Not all headaches will be related to Type 2 diabetes, but some may be.


Hypoglycamia and hyperglycamia can both lead to headaches. Hypoglycemia means low blood sugar, and hyperglycemia means high blood sugar. Both are symptoms of diabetes.


Insulin is a hormone that converts food into energy. It breaks carbohydrates down into sugar, or glucose, so it can be transported around the body in the blood.


Normally, the body matches the amount of insulin it makes to the food and drink people consume – this keeps levels stable.


In people with Type 2 diabetes, though, the process does not work properly. It means that you can end up with too much or too little sugar in their blood and this will affect how they feel.


Over time, these abnormal blood glucose levels can damage the blood vessels. This can result in long-term complications, including cardiovascular disease and stroke.


It is important to remember that diabetes itself does not cause these serious health problems, rather, they are caused by abnormal blood glucose levels. Luckily, there are lots of things you can do to manage your blood sugar levels and live well with diabetes.


Why do I get a headache with my diabetes?


Hypoglycemia and hyperglycemia can both cause headaches. They happens when there is too much or too little sugar in the blood. Both conditions affect people differently.




The NHS defines low blood sugar, which people sometimes call a hypo, as having levels of less than 4mmol/L.


People sometimes have low blood sugar during the night and wake up with a headache. The typical early signs of hypoglycemia, or low blood sugar, might include:


  • sweating
  • feeling tired
  • feeling dizzy
  • feeling hungry
  • feeling shaky
  • trembling
  • pounding or fast heartbeat
  • feeling irritable, tearful, anxious, or moody
  • pale skin


Hypoglycemia can be dangerous if people do not treat it quickly. The symptoms of more dangerous hypoglycemia are:


  • weakness
  • blurry vision
  • confusion
  • difficulty concentrating
  • feeling sleepy
  • slurred speech
  • clumsiness
  • seizures
  • passing out



What constitutes hyperglycemia is different for everyone. You will need to work with your healthcare team to decide the best target for you. In general, a normal range is between 4 and 7mmol/L before eating, and under 8.5 to 9mmol/L two hours after a meal.


The symptoms of hyperglycemia tend to build up over days and weeks. You may have no symptoms at all until your levels are very high – you may not even notice you have a problem.


Sometimes, a headache might be a sign of longer-term hyperglycemia, or high blood sugar.


The NHS has divided symptoms into warning signs and signs that require urgent medical attention. Headache falls into the second category.


Warning signs include:


  • feeling more thirsty than usual or having a dry mouth
  • needing to urinate more than usual
  • blurry vision
  • feeling tired
  • unexplained weight loss
  • frequent infections
  • fruity smelling breath


Over time, high blood sugar can lead to long-term complications. These include diabetic ketoacidosis, which is more common in Type 1 diabetes than Type 2, and hyperosmolar hyperglycaemic state (HSS), or severe dehydration.


Anyone who has hyperglycemia and one of the following symptoms should seek urgent medical attention:


  • signs of dehydration, including a headache, dry skin, and a weak heartbeat
  • feeling sick or being sick
  • tummy pain
  • diarrhoea
  • quick, deep breathing
  • a temperature of 38C or more for longer than 24 hours
  • difficulty staying awake


How can my diabetes headaches be treated?

Headaches that are related to hypoglycemia will usually go away when the underlying cause is treated.
To treat a hypo, you should follow these steps:


  1. Have a sugary drink or snack. This might be a fruit juice, a small glass of non-diet fizzy drink, or a small handful of sweets. Other options might be between three and six glucose tablets or, one or two tubes of glucose gel
  2. After 10 to 15 minutes, re-test blood sugar levels. If there is little or no change, the person should have another sugary drink or snack, and wait another 10 to 15 minutes before testing again
  3. Once the blood sugar levels return to normal, the person should either eat their next planned meal or have a snack. The snack should contain a slow-release carbohydrate, like a slice of toast or a glass of cow’s milk.


Everyone living with diabetes has a hypo from time to time, but you should you’re your healthcare team if you have low blood sugar often.


Sometimes, headaches are a sign of a serious complication of hyperglycemia. When this is the case, you might need to spend some time in hospital. Treatment for HSS, for example, will include replacement fluids and insulin by an intravenous drip.


It is important to remember that headaches are very common. While some will be connected to diabetes, many will not.


How can my I prevent diabetes headaches?


The best way to prevent diabetes headaches is to control blood glucose levels. For most people, this means working with your healthcare team to follow a care plan that will include:


  • taking any medicines as prescribed
  • following a balanced diet
  • maintaining a healthy weight
  • staying physically active
  • not smoking
  • attending regular check-ups