Skip to main content

What causes headaches during pregnancy and when to call a doctor

About 39% of pregnant and postpartum women experience headaches, so you’re not alone if you’re in that boat. They are a pain–literally–but they’re often able to be treated with something as simple as rest or water and they are often nothing to worry about. However, sometimes, they can indicate something serious is going on. Once you know the causes of pregnancy headaches, you can make an informed choice about calling your doctor.

Prostock-studio / Shutterstock

What causes headaches during pregnancy?

Your body experiences so many changes during pregnancy, and that in itself might be the reason for a headache. The sheer number and speed of changes your body is going through Another may be the change in blood flow. Your body produces 20% to 100% more blood than usual when pregnant and the increased flow throbbing through your head may be a headache culprit.

Recommended Videos

Besides higher blood volume, these are possible causes as well:

  • Hormonal changes
  • Caffeine withdrawal
  • Low blood sugar
  • Dehydration
  • Hunger
  • Vomiting
  • Stress
  • Lack of sleep
  • Sensitivity to light
  • Vision changes
  • Posture changes
  • Muscle strain and muscle tightness
  • High blood pressure
  • Sinus congestion

As you can see, this list is long but it isn’t exhaustive (though it can be exhausting!). Any one–or more–of these can cause headaches. You can get headaches from different causes throughout all three trimesters. Tension headaches are especially common in the first trimester, and headaches caused by muscle strain are more common in the third trimester.

Some of these causes can be treated (like taking a nap for lack of sleep) or prevented (like wearing sunglasses for sensitivity to light) if you can pinpoint the cause. Go down the list to see if any of them apply to you and if you can make any changes like drinking more water to help. Others, like increased blood volume or hormonal changes, cannot be changed.

Migraines may appear for some people in pregnancy when they never had them before. “Even though migraine is a genetic neurologic disease, it has many different triggers, and a drop in estrogen or change in estrogen level can be a trigger,” says Dr. Amaal Starling. The hormonal shifts can affect endless workings in your body, including causing headaches. However, if this is the culprit for you, it could be short-lived because estrogen levels in the second and third trimesters are very stable: “Because of that stability, migraine during the second and third trimesters of pregnancy will often go into remission or improve significantly.”

Image used with permission by copyright holder

When should I call a doctor about pregnancy headaches?

You should talk to your doctor regularly about any changes you experience that concern you or you are wondering how to treat. Some doctors may say taking Tylenol (acetaminophen) for a headache is okay and others may advise you against it. (Taking aspirin and ibuprofen are generally not recommended.)

They may recommend rest, ice packs, heating pads, stretches, massage, exercise, or other home remedies depending on what they suspect is the cause. You may also want to avoid migraine trigger foods like chocolate and dairy.

Your doctor can test your blood pressure, blood sugar, vision, and other factors to see what is causing your headaches. They might also want to make sure your headache isn’t being caused by high blood pressure or something else that needs treatment for the safety of you and your baby. Headaches in the second and third trimesters can be a sign of preeclampsia, a serious condition.

“Headaches are common in women both in and outside of pregnancy,” according to Dr. Kelley Saunders, “but whether they are normal or not should always be discussed with your doctor.”

One important reason to tell your doctor about your headaches is that if the cause is high blood pressure, this can raise the risk of stroke, preterm delivery, placental abruption, and other issues. Headaches can also accompany other issues your doctor needs to know about like diabetes, sinus infection, or blood clots.

Give your doctor a call if:

  • Your headache is accompanied by other symptoms like blurred vision, abdominal pain, puffiness in your hands or face, or fever
  • You’re unsure how to most safely and effectively treat your headache(s)
  • Your headache lasts more than three hours
  • Your headaches are persistent, chronic, or interfering with your daily life
  • Your headaches get worse than before or you have a headache for the first time ever
  • None of the remedies you tried worked
  • You’re worried about your headache(s)

Most of the time a headache in pregnancy is caused by nothing to worry about, but in the rare case it signals preeclampsia or another serious condition, it’s best to let your doctor know.

Sarah Prager
Sarah is a writer and mom who lives in Massachusetts. Her writing has appeared in The New York Times, The Atlantic, National…
How to estimate fetal weight with a fetal weight calculator
Here's why estimated fetal weight is important
A pregnant woman holding a laptop in her lap while holding her belly

There are several different reasons why your doctor will estimate your baby's fetal weight throughout your pregnancy. For expectant parents, there's endless fascination in discovering everything possible before the baby is born, including birth weight. But, knowing how much your baby weighs while in the womb isn't just a good way to help mentally prepare for childbirth, it's also an important marker for fetal development that can impact wellness outcomes during childhood and adolescence.

Low birth weight can affect brain development in infancy and childhood, as studies have shown that it impacts cerebral cortex development well into adolescence. The cerebral cortex is the area of the brain responsible for functions such as consciousness, thought, emotion, reasoning, language, and memory. It's a pretty big deal.

Read more
How to recognize the signs of implantation and early pregnancy
Early signs and symptoms of pregnancy
Woman holding a pregnancy test

We all know that your body goes through many changes when you're pregnant, but what about when you actually conceive? Trying to get pregnant makes you hyper-aware of your body, and you'll probably find yourself looking for any indication that implantation has happened. Implantation is when an embryo implants into the uterine lining to start growing into a fetus.

Implantation, like pregnancy, is different for everyone, so while some could experience implantation symptoms like some bleeding or cramping, similar to a very light period, for others, nothing may happen. Following implantation, pregnancy symptoms will begin and increase as the days progress. Read on to find out exactly what to expect in signs of implantation.
What is implantation?

Read more
7 early pregnancy symptoms you shouldn’t ignore
Check out these early signs of pregnancy that are often mistaken for other conditions
Woman sitting on couch and looking at a pregnancy test

Pregnancy symptoms can feel like a lot of different things. Maybe it's PMS, or you're tired from a long week at work, or maybe, all that stress you've been experiencing is taking its toll. Whatever the cause, if you’ve been feeling rather odd lately, you may be wondering if you could be pregnant. Or are you simply imagining some of the physical and mental changes that are happening?

The early pregnancy symptoms that occur in the first two weeks seem so subtle that anybody can easily mistake them for another condition. To find out more information about what to expect shortly after conception, read on. You might feel reassured that these signs are not wishful thinking (or the flu) and that yes, you’re actually pregnant.
Most common early pregnancy symptoms and signs almost anyone can miss

Read more