How Blood Pressure Changes Across the Menstrual Cycle

May. 20, 2025

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Many women wonder if their blood pressure readings change during their menstrual cycle. For women with sustainably high blood pressure (hypertension), this question is important. Our bodies go through hormonal shifts each month. These shifts can cause subtle changes in blood pressure.

Menstrual Cycle Blood Pressure Fluctuations

A normal menstrual cycle has several phases. The follicular phase is the first half, starting with the menstrual period itself. The luteal phase is the second half, after ovulation, leading up to the next period. Hormone levels rise and fall during these phases. Estrogen is a key female hormone that peaks around ovulation (mid-cycle). Progesterone is another hormone that rises in the luteal phase after ovulation.

Research shows that blood pressure can vary slightly with these hormonal changes. In many women, blood pressure is highest at the very start of the period (day 1 of the cycle) and then becomes a bit lower in the mid-luteal days. One study found that blood pressure was lowest roughly between day 17 and day 26 of the cycle (toward the end of the luteal phase). The changes were small – only a few millimeters of mercury (mmHg). These shifts happened in women with normal blood pressure and in women with mild hypertension alike. This means both groups showed a similar pattern of a mild rise and fall across the month.

It is important to note that these fluctuations are usually very mild. Doctors consider them normal. You might not even feel a difference. Daily factors like stress, salt intake, and sleep have a much bigger impact on blood pressure than menstrual phase does. So, if you notice your home readings vary by a few points, it could be part of your normal cycle. Many women don’t realize their cycle plays a role at all until they start tracking readings over several weeks.

Why Menstrual Cycle Blood Pressure Changes Happen

What causes these small blood pressure changes? The answer lies in hormones. Hormones are chemical messengers in the body. During the cycle, levels of estrogen and progesterone change. Estrogen (a hormone that rises before ovulation) helps blood vessels relax. It stimulates the production of nitric oxide, a molecule that widens blood vessels. Wider vessels mean blood can flow more easily, which can lower pressure. This effect might contribute to slightly lower blood pressure in the middle of the cycle when estrogen peaks.

Progesterone (the hormone high in the luteal phase after ovulation) has different effects. Progesterone can cause the body to retain sodium and water. It does this partly by influencing aldosterone (a hormone that controls salt balance). When more fluid is in the bloodstream, blood pressure can rise. Progesterone may also activate the renin-angiotensin system, a body system that can increase blood pressure by tightening blood vessels and retaining fluid. However, progesterone isn’t all bad – it also has a mild calming effect on the blood vessel walls in some cases. The net result is that in the second half of the cycle some women experience a slight uptick in blood pressure due to progesterone’s fluid retention effects.

Other factors come into play too. Ovulation (when the ovary releases an egg, mid-cycle) can cause a brief shift in hormones and even a slight inflammatory response. A few studies noted that some women with hypertension have a small blood pressure spike around ovulation. For example, in one 24-hour monitoring study, women with high blood pressure showed a noticeable increase in blood pressure during the ovulation phase of their cycle, while women without hypertension did not. This suggests that if you already have high blood pressure, your body may react more to the hormonal surge of ovulation. The reasons are not fully clear. It could be related to how an individual’s body handles sodium or differences in other hormones like testosterone. But again, this rise is usually temporary.

Menstrual period can influence blood pressure in a couple of ways. At the very start of your period, you might have menstrual cramps or pain. Pain can trigger a stress response in the body, briefly raising heart rate and blood pressure. That could explain why day 1 readings can be a bit higher. On the other hand, during your period you are also shedding blood. Heavy menstrual bleeding in some cases can lead to a lower blood volume, which might drop your blood pressure. If a woman has an extremely heavy period (losing a lot of blood), she could even feel dizzy or faint due to lower blood pressure. This is not typical for most, but it can happen if there is significant blood loss and resulting anemia (low red blood cell count).

Premenstrual symptoms (PMS) in the days before the period might also impact blood pressure slightly. Some women feel bloated and notice swelling before their period; this is due to water retention influenced by hormones like progesterone and aldosterone. That fluid retention can cause a minor rise in blood pressure. Additionally, PMS can involve mood changes and stress. Anxiety or tension in the premenstrual phase might push blood pressure a bit higher for some women. However, studies so far show mixed results. Any blood pressure increase from PMS is usually small. If you do feel moody or stressed before your period, practicing relaxation techniques (like deep breathing or gentle yoga) might help both your mood and blood pressure.

Menstrual Cycle Blood Pressure and Hypertension Management

For women of active age who have high blood pressure, understanding these patterns can be empowering. The changes due to the menstrual cycle are subtle, but knowing about them can help you interpret your readings more calmly. If you measure your blood pressure at home, try noting what day of your cycle you are on. You might notice a pattern after a few months. For instance, maybe your readings run a few points higher the day before your period. If you see a consistent trend, you can plan around it. For example, some women reduce their salt intake or ensure they get extra sleep in the days they expect a slight rise.

It’s also important not to overreact to one or two higher readings if they coincide with a hormonal phase. Let’s say your blood pressure is usually well-controlled, but one day it’s a bit elevated and you realize your period started that morning. In that case, take a deep breath and re-check later. It could be a temporary bump. Of course, if your blood pressure is very high or you feel symptoms (like severe headache or chest pain), you should seek medical advice regardless of the cycle day.

Lifestyle and medication remain the cornerstone of blood pressure control. Hormonal fluctuations won’t ever be as significant as the impact of a healthy diet, regular exercise, and taking your prescribed medications. Do not skip or change your blood pressure medication based on the phase of your cycle without consulting your doctor. The cycle might fine-tune your numbers slightly, but it doesn’t replace medical management.

If you experience symptoms around your period that concern you – for example, feeling unusually dizzy during your period or very tense and headachy before it – talk to your healthcare provider. They might check if those symptoms are linked to blood pressure swings or something else. In some cases, doctors might time certain tests or evaluations considering your cycle. But generally, for routine blood pressure management, you don’t need special adjustments for each phase. Just be aware and track how you feel.

Facts Few Know

Severe PMS and future hypertension: Women who have moderate to severe premenstrual syndrome are at higher risk of developing chronic high blood pressure later in life. One long-term study found that women with significant PMS had about a 40% greater chance of developing hypertension compared to women without PMS. This suggests PMS might be an early indicator of higher blood pressure risk in some women.
Birth control pills can raise blood pressure: If you use hormonal birth control (like the pill), it can slightly increase your blood pressure. Many women don’t realize this. The estrogen in birth control pills can cause a small rise in blood pressure by affecting blood vessel walls and kidney function. It’s usually a minor increase, but if you already have high blood pressure, discuss contraceptive options with your doctor. Sometimes a pill with lower estrogen or a non-hormonal method may be recommended.
Menopause’s impact overshadows monthly changes: The menstrual cycle affects blood pressure only a little, but once cycles stop (menopause), blood pressure tends to increase more noticeably. After menopause, women lose the protective effects of estrogen on the heart and blood vessels. This is why post-menopausal women often see higher blood pressure and a rising risk of heart disease. It’s a reminder that while monthly fluctuations are small, the bigger picture of a woman’s life stages plays a major role in blood pressure health.

Remember, every woman’s body is unique. Some may notice slight blood pressure changes with their cycle, while others notice nothing. The key is maintaining healthy habits all month long. By eating well, staying active, managing stress, and following your treatment plan, you can keep your blood pressure in check through all phases of your cycle.