Why do I get a headache after I eat?

In this brief blog we will answer the question,” Why do I get a headache after I eat?” We will discuss some causes of headaches after eating. We will also discuss some common compounds that trigger migraines.

Why do I get a headache after I eat?

If you notice that you experience a headache after eating you may be having a condition known as postprandial headache. Postprandial translates to after eating. Apart from a postprandial headache there are also other factors that can contribute to this, we will look into them shortly.

What causes my head to hurt after eating?

Postprandial hypoglycemia

Postprandial hypoglycemia is a condition whereby you experience a headache 2 to 5 hours after consuming food. It is also known as  reactive hypoglycemia and is usually caused by a drop in blood sugar levels. 

When you eat food, the body uses the carbs as energy. The carbohydrates are broken down into sugars which increases the sugar levels in your blood until the cells use it as a fuel source. Postprandial hypoglycemia signifies that the sugar levels in your blood are low after having a meal. Some of its causes are:

Some causes include:

  • diabetes
  • abnormal hormone levels
  • digestive tumors

Food allergy

Food allergies do not only have symptoms such as hives, they can also result in migraines attacks. When you are allergic to a particular food, the body automatically responds to its presence by attacking. It uses the antibodies to help fight any allergy in what is known as an allergic reaction.

Therefore if you find that you usually experience headaches after consuming a particular type of food or ingredient, it could possibly mean that you are allergic to it.

Food intolerance

Food intolerance is sometimes often confused with food allergy. Food allergy usually triggers the immune system with even tiny portions of that food resulting in a reaction. Food intolerance on the other hand usually affects the digestive system and has less severe symptoms. Causes of Food intolerance include:

  • Lack of an enzyme required for digestion of the food. This is the case for people that are lactose intolerant
  • Irritable bowel syndrome (IBS). This condition usually results in symptoms such as  cramping, constipation and diarrhea.
  • Sensitivity to food additives.Some people are usually sensitive to sulfites which are used in wines and canned foods, dried fruits. Sulfites can trigger asthma attacks in asthmatics.

Although most symptoms of Food intolerance are usually digestive in nature, it can as well result in headaches.

Temporomandibular disorder (TMJ)

The temporomandibular joint (TMJ) are the 2 joints that slide and rotate in front of each one of your ears. They also  connect your lower jaw (the mandible) to your skull.

TMJ disorders are usually exhibited by a clicking or popping sound and can as well be a tight feeling on each side of the jaw when you close or open your mouth. As a result of the proximity of the affected joint to the head area, chewing of food can as well result in pain and cause a headache.

Cold stimulus

A headache caused by a cold stimulus is also known as brain freeze or “ice cream headache.” It is usually as a result of eating or drinking something that’s frozen or very cold. Most of these headaches usually last for minutes but can sometimes last upto an hour. They can also be triggered by cold weather.

Scientists believe that they occur due to changes in the blood vessels surrounding certain nerves as a response to cold temps.

What are some common migraine trigger compounds?


Caffeine is a common trigger for headaches. Caffeine Is a common active ingredient in many medicines because of its ability to narrow the blood vessels and hence reduce pain. Regular consumption of caffeine can however make your body become more dependent on it. It can cause withdrawal symptoms such a s migraines.


Nitrates are commonly used in foods as an additive to cure meat and other perishable produce. Nitrates can result in migraines by exposure of the brain to nitric oxide which usually constricts the blood vessels. 


Phenylethylamine is derived from aminoacids. They can trigger migraines by restriction of blood blood flow as well as the circulatory system. 


In this brief blog we have answered,” Why do I get a headache after I eat?” We have discussed some causes of headaches after eating. We have finally discussed some common compounds that trigger migraines.



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