Dr Gillian with a patient

Hormones, Blood Pressure & Migraines: What’s the Link?

If you’ve ever suffered from migraines, you’ll know they’re not just ‘bad headaches.’ They can be utterly debilitating—throbbing pain, nausea, visual disturbances, and an overwhelming need to hide in a dark room until the storm passes. But did you know that migraines often come and go at particular life stages and often have a connection to other health conditions like high blood pressure, Reynaud’s and pre-eclampsia?

So what links all these phenomena? Hormones. Specifically, oestrogen.

Fluctuations in oestrogen levels throughout life—during puberty, pregnancy, menopause, and even monthly menstrual cycles—can have a profound impact on the brain’s vascular system. And because blood pressure, migraines, and pre-eclampsia all have roots in how our blood vessels function, it’s no surprise that they’re all interconnected. Let’s get into what a migraine actually is:

At their core, migraines are thought to stem from a mix of genetic, vascular, and neurological factors. The brain of a migraine sufferer is hypersensitive, meaning it overreacts to certain triggers—like hormonal shifts, stress, or even certain foods—leading to a cascade of events in the nervous system and blood vessels. One key feature of migraines is ‘aura’—a set of warning signs that can appear before the pain kicks in. Aura is caused by a wave of electrical activity spreading across the brain, temporarily altering vision, speech, or sensation. Some people see zigzag lines, flashing lights, or experience numbness and tingling, while others feel confused or struggle to find words. Not everyone gets aura, but for those who do, it’s a sign that the migraine process has already begun.

Why Are Migraines So Tied to Oestrogen?

Oestrogen plays a crucial role in the nervous system and vascular health. It helps regulate blood flow, inflammation, and the way blood vessels expand and contract. When oestrogen levels drop suddenly—such as just before a period, postpartum, or during perimenopause—it can trigger a cascade of events in the brain’s blood vessels that lead to migraines.

This explains why:

  • Migraines often start in puberty when oestrogen fluctuations first kick in.
  • They tend to improve during pregnancy when oestrogen levels remain high and stable.
  • They can worsen around perimenopause due to erratic oestrogen changes.

But migraines don’t just happen in isolation—they are also linked to changes in blood pressure.

Migraine & Blood Pressure: A Two-Way Relationship

Blood pressure is all about how forcefully blood is moving through your arteries. If it’s too high (hypertension) or too low (hypotension), it can affect blood flow to the brain, triggering migraines.

  • High Blood Pressure (Hypertension) – This can put stress on the arteries in the brain, making them more likely to spasm, which is one of the key mechanisms behind migraines.
  • Low Blood Pressure (Hypotension) – This can reduce oxygen supply to the brain, which can also set off a migraine.

The link works both ways: not only does blood pressure influence migraines, but migraines (especially those with aura) are also associated with a slightly higher risk of developing high blood pressure later in life.

This is particularly relevant for women, as hormonal changes can directly impact blood pressure levels and external hormones like in HRT or contraception have to be given with caution (or not at all) in some women who have significant migraine as the risk of having a stroke is also directly related to high oestrogen levels for these women.

Pre-Eclampsia: When Hormones, Blood Pressure & Migraines Collide

Pre-eclampsia is a pregnancy complication characterised by high blood pressure, protein in the urine, and signs of organ stress—particularly affecting the kidneys and liver. Women who have experienced migraines before pregnancy are at a higher risk of developing pre-eclampsia. But why?

During pregnancy, the placenta plays a huge role in regulating blood pressure and vascular function. Oestrogen and progesterone levels rise significantly to support the growing baby, but in some women, the blood vessels don’t respond as they should. This can lead to constricted arteries, reduced blood flow to the placenta, and a rise in blood pressure—hallmarks of pre-eclampsia.

Migraines and pre-eclampsia share similar underlying mechanisms, such as:

  • Vascular Dysfunction – Both conditions involve abnormal responses in the blood vessels.
  • Inflammation & Oxidative Stress – Increased inflammation and oxidative damage contribute to both migraine episodes and pre-eclampsia.
  • Blood Pressure Instability – Women with a history of migraines often have greater fluctuations in blood pressure, which may predispose them to developing pre-eclampsia.

Women who develop pre-eclampsia are also more likely to experience migraines postpartum and have a higher lifetime risk of cardiovascular disease including high blood pressure.

The Menopausal Shift: Why Migraines Can Get Worse Before They Get Better

As menopause approaches, oestrogen levels start to fluctuate wildly before eventually declining for good. For some women, this makes migraines worse than ever, especially during perimenopause when hormone levels are unpredictable.

The key factors at play include:

  • Erratic Oestrogen Drops – These can cause blood vessels to spasm more frequently, triggering migraines.
  • Progesterone Decline – This hormone has calming effects on the nervous system, so when it drops, migraines can become more intense.
  • Sleep Disturbances & Stress – Menopause often brings sleep disruption and increased stress, both of which are well-known migraine triggers.

The good news? Once menopause is fully established and oestrogen levels stabilise, many women find their migraines improve or even disappear.

HRT and Migraines

When it comes to HRT and migraines, the relationship is anything but straightforward. For some women, HRT can be a game-changer, stabilising hormone levels and reducing the frequency or severity of migraines. This is particularly true when using body-identical oestrogen in a steady, transdermal form (like patches or gel), which avoids the peaks and troughs that can trigger attacks. However, for others, HRT can make migraines worse, particularly if taken in tablet form, which causes more fluctuations in oestrogen levels. Progesterone can also play a role—some women find that certain types (like synthetic progestins) worsen headaches, whereas micronised progesterone (Utrogestan) may be better tolerated but this is highly individual. It often takes some trial and error to find the right balance, but working with someone who has experience in this area (like myself!) can make the world of difference.

Managing Migraines Through Hormonal Stages

Understanding the connection between hormones, blood pressure, and migraines means we can take steps to manage them more effectively.

  • Track Your Triggers – Keep a diary of when migraines occur in relation to your cycle, stress levels, and sleep patterns.
  • Balance Blood Sugar – Fluctuations in blood sugar can make hormonal swings more dramatic as it puts pressure on the autonomic nervous system. Eating protein, healthy fats, and fibre regularly can help stabilise blood sugars. Anecdotally, I’ve had clients who have completely resolved, or at least substantially improved, their migraines and/or menopausal hot flushes by following a diet free from processed (flour/sugar based) carbohydrates. Eating a diet full of whole foods will boost B vitamin and magnesium levels in a safe and natural way too, which also helps blood vessel relaxation.
  • Optimise Hydration – Dehydration makes blood vessels constrict, increasing migraine risk. Aim for steady water intake throughout the day with front loading in the morning to avoid overnight toilet breaks!
  • Explore HRT (Hormone Replacement Therapy) – For women struggling with menopausal migraines, carefully managed HRT can sometimes help smooth out hormone fluctuations.

Final Thoughts

Migraines, blood pressure, pre-eclampsia, and hormonal shifts are all intricately connected. While oestrogen plays a protective role in blood vessel function, its fluctuations throughout life can be a double-edged sword—helping at times and wreaking havoc at others.

If you experience migraines, especially alongside blood pressure issues or a history of pre-eclampsia, understanding this link can be the first step towards finding the right management strategy. Sometimes an explanation is as good as a cure!