Dr. Kundlas
A headache after eating usually comes from what or how you ate: a big or salty meal, alcohol, a migraine trigger food, very cold food, or swings in blood sugar or blood pressure. Keeping a simple food and headache diary for two to three weeks is often the fastest way to find your pattern. A sudden, severe headache, or a headache with weakness, confusion, trouble speaking or swelling of the lips or throat, is an emergency, so call 911.
If headaches after meals happen often, a visit with a primary care doctor in Sebring can help look at blood sugar, blood pressure and food triggers.
Common causes of a headache after eating
Blood sugar that drops or spikes
Low blood sugar can cause a headache along with shakiness, sweating, hunger, a fast heartbeat or irritability. It is most likely in people with diabetes who take insulin or a sulfonylurea pill (glipizide, glyburide or glimepiride), especially if a meal was small, late or low in carbohydrates. Some people without diabetes get a dip in blood sugar two to four hours after a high sugar meal, called reactive hypoglycemia.
High blood sugar after a large, starchy or sugary meal can also cause headache, tiredness and thirst, especially in people with diabetes or prediabetes. If you notice this pattern, it is worth checking your sugar or your A1c.
Blood pressure changes
Blood pressure can move in either direction after a meal.
- Salty meals, alcohol and large meals can push blood pressure up in some people. Very high blood pressure can cause a headache, often at the back of the head.
- In some older adults, blood pressure drops after a meal as blood flows to the gut. This is called postprandial hypotension. It can cause lightheadedness, a dull headache, blurry vision or even fainting, usually 30 to 60 minutes after eating. It is more common in people with diabetes, Parkinson’s disease, or who take blood pressure medicines. If this happens to you, tell your doctor, and do not change the timing of any medicine on your own.
Migraine trigger foods
If you get migraines, certain foods and drinks can set one off. Common triggers include:
- Aged cheeses
- Processed meats with nitrates, such as hot dogs, bacon and deli meats or nitrites, such as hot dogs, bacon and deli meats
- Alcohol, especially red wine
- Pickled, fermented or smoked foods
- Artificial sweeteners such as aspartame, for some people
Triggers are personal. Most people with migraine react to a few foods, not all of them.
MSG
Many people blame monosodium glutamate (MSG) for headaches after Chinese food or packaged snacks. The FDA considers MSG safe, and careful studies have not shown that normal amounts cause headaches in most people. A small number of people seem sensitive to large amounts, usually eaten without food. If you notice a pattern, it is reasonable to limit MSG and see whether it helps.
Cold food or drinks (“brain freeze”)
A sharp headache in the forehead or temples right after ice cream or a cold drink is a cold stimulus headache. It usually passes in less than a minute. Eating cold foods more slowly and holding them in the front of the mouth helps. This is one of the most common reasons for an immediate headache after eating.
Caffeine withdrawal
If you usually drink coffee with breakfast or lunch and skip it, a headache can start a few hours later. This can feel like a headache after eating when it is really a headache from missing caffeine. Keeping caffeine at a steady amount, or cutting back slowly, prevents it.
Eating too fast, too much, or not drinking enough
Large meals, eating quickly and not drinking enough water can all bring on a headache. Being low on fluids is common in Florida summers.
Food allergy or intolerance
A true food allergy usually causes hives, itching, swelling, vomiting or breathing trouble, not headache alone. Celiac disease and other food intolerances can cause headaches along with belly pain, bloating or diarrhea.
Jaw problems and chewing
TMJ problems can cause a headache at the temples after chewing tough or chewy foods. In adults over 50, new headache with jaw pain while chewing, scalp tenderness, or vision changes can be a sign of giant cell arteritis, an inflammation of the arteries. This needs to be checked the same day, because it can cause vision loss if untreated.
“Pressure headache after eating”
A pressure or tight band feeling after meals is often a tension type headache, sinus pressure, or a blood pressure change. If pressure headaches keep happening after meals, check your blood pressure about 30 to 60 minutes after eating and bring the readings to your doctor.
How to prevent headaches after eating
- Eat regular meals, and do not skip meals, especially if you take insulin or a sulfonylurea
- Include protein, fiber and healthy fat with carbohydrates to avoid sharp sugar swings
- Choose smaller meals, and eat slowly
- Drink water through the day
- Limit salty processed foods and alcohol
- Keep your caffeine about the same each day
- Write down what you ate, when the headache started, and how bad it was, for two to three weeks
- If you check your blood sugar or blood pressure at home, take a reading when a headache starts
For an occasional mild headache, acetaminophen (Tylenol) is usually the first choice for adults over 50; follow the dosing on the label. Using pain relievers more than two or three days a week can cause rebound headaches. Avoid ibuprofen or naproxen, or ask your doctor first, if you have kidney disease, heart disease, stomach ulcers, or take a blood thinner.
When to see a doctor
Make an appointment if:
- Headaches after eating happen often or are getting worse
- You are over 50 and the headaches are new for you
- You think you may be having low or high blood sugar episodes
- Your home blood pressure readings are often 130/80 or higher, or you feel faint after meals
- Headaches come with belly pain, diarrhea or weight loss
- You need pain relievers more than two days a week
Get a same day visit for a new headache with jaw pain while chewing, scalp tenderness or blurry vision.
CALL 911 RIGHT AWAY IF:
- You have a sudden, severe headache, the worst of your life, that peaks within a minute or so
- A headache comes with face drooping, arm or leg weakness, trouble speaking, confusion or loss of vision (possible stroke)
- A headache comes with a stiff neck and fever
- Your blood pressure is 180/120 or higher and you have a headache, chest pain, shortness of breath, vision changes, weakness or confusion
- After eating, your lips, tongue or throat swell, or you have hives with trouble breathing or swallowing
- You take an MAOI medicine and get a sudden, pounding headache after aged cheese, processed meat or wine
- Someone with diabetes on insulin or a sulfonylurea has low blood sugar and is confused, very drowsy, passes out, or cannot swallow safely. Do not put food or drink in the mouth of someone who cannot swallow. Use glucagon if it has been prescribed.
If you take insulin or a sulfonylurea and feel shaky, sweaty or confused, check your sugar. If it is below 70 mg/dL, follow the rule of 15: take 15 grams of fast acting sugar (4 ounces of juice or regular soda, or glucose tablets as the label directs), wait 15 minutes and check again. Repeat if it is still below 70. Call 911 if it does not come up, or if the person becomes confused, very drowsy or cannot swallow safely.
Frequently asked questions
Why do I get a headache after I eat?
The usual reasons are blood sugar swings, blood pressure changes, migraine trigger foods, alcohol, large or salty meals, cold food, not drinking enough, or missing your usual caffeine. A food and headache diary is the simplest way to find your cause.
Can low blood sugar cause a headache after eating?
Yes. People who take insulin or a sulfonylurea can get low blood sugar if a meal was small or late. Some people without diabetes get a dip a few hours after a high sugar meal. Shaking, sweating and hunger along with the headache are clues.
Why do I get a headache right after eating?
A headache within a minute of cold food is likely brain freeze. A headache after chewing can come from the jaw joint. In adults over 50, new headache with jaw pain while chewing should be checked the same day.
What causes a pressure headache after eating?
Pressure headaches after meals are often tension type headaches, sinus pressure, or blood pressure changes. Check your blood pressure after a meal when it happens and share the readings with your doctor.
Does MSG cause headaches?
Research has not shown that normal amounts of MSG cause headaches in most people. A few people may react to large amounts. If you notice a pattern, limiting it is reasonable.
Can high blood pressure cause a headache after eating?
It can. Salty meals and alcohol can raise blood pressure in some people. A headache with a reading of 180/120 or higher and other symptoms such as chest pain, vision changes or confusion is an emergency.
Getting checked in Sebring or Lake Wales
Headaches after eating often have a simple cause that a primary care visit can sort out. We can check your blood pressure, blood sugar and A1c, review your medicines, and go over your headache diary with you.
Shield Medical Group has two offices:
- Sebring: 4597 Casablanca Cir, Sebring FL 33870. Phone (863) 236-9550. Monday to Friday 8 a.m. to 5 p.m., Saturday 10 a.m. to 1 p.m.
- Lake Wales: 23607 US Highway 27 N, Lake Wales FL 33859. Monday to Friday 8 a.m. to 5 p.m.
You can book an appointment, and walk-ins are welcome for new and established patients. We accept many Medicare Advantage plans, so call to ask about yours.
Medical disclaimer
This article is for general education only and is not medical advice. It does not replace an exam by your own doctor. If you think you are having a medical emergency, call 911.
