What Is the Keto Headache, and How Do You Treat It?
The ketogenic diet is a popular eating pattern that replaces most of your carbs with fat.
Though this diet appears to be effective for weight loss, many people experience uncomfortable side effects when first starting the diet. Headaches are one of the most common symptoms.
If you’re considering keto, you may wonder how best to stave off these headaches.
This article explores the causes of headaches on the keto diet and offers tips for preventing and treating them.
What causes headaches on keto?
Several factors may cause keto headaches, which typically occur when you’re beginning the diet.
Low blood sugar levels
Glucose, a type of carb, is the main source of fuel for your body and brain.
The keto diet drastically reduces your carb intake, replacing it with fat. This shifts your body into ketosis, a metabolic state in which you burn fat as your primary source of energy (1Trusted Source).
When you start the diet, your body begins relying on ketone bodies instead of glucose, which can cause your blood sugar levels to drop. In turn, this may lead to low blood sugar.
This transition into ketosis may stress your brain, which could result in mental fatigue, or brain fog, as well as headaches (2Trusted Source, 3Trusted Source).
Dehydration is one of the most common side effects of the keto diet. It occurs because people tend to urinate more frequently as they shift into ketosis.
During this transition, your body depletes its stored form of carbs, called glycogen. Given that the glycogen in your body is bound to water molecules, it releases water when it’s used up (4Trusted Source).
Furthermore, your body produces less insulin — a hormone that helps absorb glucose from your blood — on keto because you consume fewer carbs. A drop in insulin levels can affect electrolytes, such as potassium and sodium, which play key roles in hydration.
For example, your kidneys release excess sodium when insulin levels fall, promoting dehydration (5Trusted Source).
Collectively, these factors can contribute to headaches.
Aside from headaches, signs of dehydration include dry mouth, dizziness, and impaired vision (6Trusted Source).
Other potential causes
Several other factors may increase your risk of headaches on the keto diet.
These include the overuse of medications, diuretics, and other drugs that promote dehydration, as well as your age and lifestyle factors like poor sleep, stress, and skipping meals (7Trusted Source).
SUMMARYLow blood sugar levels and dehydration are two significant drivers of keto headaches. Multiple other medicinal and lifestyle factors may likewise increase your headache risk.
Many people experience side effects beyond headaches on the keto diet, including muscle cramps, constipation, fatigue, and dizziness. These symptoms are collectively known as the keto flu (6Trusted Source).
In most instances, dehydration and electrolyte imbalances can worsen these symptoms, making prevention especially important.
Tips to treat or prevent keto headaches
Ensuring proper hydration and eating plenty of nutritious foods can help minimize your risk of dehydration. In turn, this can alleviate headaches — and prevent them from occurring in the first place.
Here are several specific tips:
- Drink plenty of water. As the initial phases of keto involve water loss, it’s important to drink adequate fluids. Aim for at least 68 ounces (2 liters) of water each day.
- Limit your alcohol intake. Alcohol is a diuretic, which means it makes you urinate more often and may increase your risk of dehydration (8).
- Eat more low carb, water-rich foods. Cucumbers, zucchini, lettuce, celery, cabbage, and raw tomatoes have a high water content, which can help you stay hydrated. Some of them are also good sources of electrolytes.
- Eat more electrolyte-rich foods. Keto-friendly foods like avocados, spinach, mushrooms, and tomatoes are high in potassium. Similarly, almonds, kale, pumpkin seeds, and oysters are high in magnesium and suitable for keto (9Trusted Source, 10).
- Salt your food. Consider lightly salting your food to reduce your risk of an electrolyte imbalance.
- Try an electrolyte supplement. Taking an electrolyte supplement may minimize your risk of dehydration and keto flu symptoms.
- Avoid intense exercise. Refrain from intense workouts during the initial days of keto, as they can stress your body and increase your likelihood of headaches.
If you continue to experience headaches after several days or weeks on the keto diet, consult a health professional to ensure that an underlying medical condition isn’t to blame.
SUMMARYMinimizing your risk of dehydration and electrolyte imbalances is key to combatting headaches on the keto diet. Among other steps, you can try drinking plenty of water, eating water-rich foods, limiting alcohol, and salting your foods.
Though the ketogenic diet is a great tool for weight loss, it may cause several side effects when you’re first starting out.
Headaches are one of the most common side effects of this diet, and they’re typically triggered by dehydration or low blood sugar levels.
Nonetheless, you can protect against keto headaches by drinking plenty of water and keeping a close eye on your electrolyte levels, among other tactics.
If your headaches persist beyond a few days or weeks, talk to a healthcare professional.
If you recently started a keto diet and are getting headaches, brain fog, or mental fatigue, don’t be surprised or overly concerned. You’re likely experiencing some of the common (but not fun) side effects that come with transitioning from a carb (glucose)-based diet to a ketone (fat)-based diet. The good news is that these symptoms are temporary. Also, there are things you can do to help them go away or to be less bothersome while your body settles into the ketogenic lifestyle.
What Causes Headaches on a Keto Diet?
When you transition out of a typical carb-heavy diet into a low-carb, moderate protein, and higher fat diet, your body takes some time to adjust, typically one to two weeks. This adjustment period is a lot like detoxing. In fact, you are detoxing from a sugary (glucose) diet. As such, it’s normal to experience a variety of detox-like or flu-like symptoms, commonly called the keto flu. One of the symptoms is headaches, which makes sense if you understand the transition process.
Low Blood-Sugar Headaches
Your brain is used to being powered by glucose (the product of a high-carb diet) rather than ketones (the product of a higher fat, low-carb diet). When you begin a keto diet, your body continues reaching for glucose, even when it’s no longer available and is instead creating ample ketones for energy. This can cause your blood glucose to drop too low (typically below 70 mg/dL), especially if you are intermittent fasting and, if you’re not yet keto-adapted, can become hypoglycemic(1). In this case, becoming hypoglycemic is not cause for alarm. It’s part of the transition. However, since your body isn’t used to it, this new low blood-sugar (no glucose) can briefly add stress to your brain and nervous system(2), and consequently give you a headache, as well as strong hunger and brain fog. Once your body starts utilizing its ketones rather than glucose, you should find some relief from your headache.
Notice your weight comes off quickly when you start keto? This is actually water loss. When you’re in the transition stage of keto and using up your stored glucose (glycogen), your body excretes extra water. This is because every gram of glycogen is stored and released with three grams of water(3). So, as your body rids itself of all its glucose reserves, it also eliminates significant amounts of water (and the bloating that goes along with it). If you aren’t replenishing that water by drinking frequently and plentifully, you’ll get dehydrated—and also perhaps get the headache that accompanies dehydration. (You know hangover headaches? Same idea.)
Also, when you cut way back on eating carbs, your body makes less insulin. Since insulin’s job is to process the glucose in carbs, when you stop eating carbs, your body needs and thus produces less insulin. With less insulin in your system, your kidneys excrete more sodium, one of the electrolytes that regulate your hydration(4). This sodium excretion can throw off the balance of other essential electrolytes too, such as potassium and magnesium. This imbalance is one of the main reasons people suffer keto-flu symptoms. If you find yourself getting a headache while on keto, it may be related to sodium loss.
Toxins from Stored Fat
When your body begins to use fat for fuel instead of glycogen, it reaches into your fat stores. But these fat stores also store toxins. As the body breaks down its fat, these toxins are released into your bloodstream, potentially causing headaches, dizziness, and fatigue.
There’s a lot of misinformation and anecdotal information about the topic of hormones and ketones, yet what is abundantly clear in the literature is ANY diet that results in rapid weight loss or restricts calories (which some folks do initially on keto to help lower the appetite), will change diurnal rhythm (daily patterns) and signal hormonal changes. It’s also true that drops in insulin levels will directly lower estrogen levels. Most folks today are dealing with estrogen dominance thanks to blood sugar imbalance, stress, exogenous hormone disrupting chemical exposure, poor sleep patterns and blue light/screen time excess, all of which creates hormone imbalance.