In medical terms, ʻmenopauseʼ is defined by a woman’s last natural period. However, we generally also use ʻmenopauseʼ to describe the time in life when periods become irregular and hot flushes occur. These symptoms result from changes in the ageing ovaries and can start around ten years before a woman’s last menstrual period. Headaches are common during this time, affecting over 90% of women.
Migraine tends to worsen in the years leading up to the menopause, with attacks occurring more frequently and sometimes also lasting longer. Many women notice more of a link with their periods. In the early stages of menopause, when periods become erratic and more frequent, this also means more migraines. Towards the end of menopause, as periods lessen, so does migraine. For women who have noticed a strong link between migraine and hormonal triggers, post-menopause can be a blessing as migraine is very likely to improve. This may take two or three years after the last period, as it can take this long for the hormones to settle. Non-hormonal triggers can still persist after menopause so if these are important causes for migraine, attacks will still continue.
The main reason for worsening migraine during menopause is the fluctuation of oestrogen. This is also responsible for initial worsening of migraine at puberty, as it can take a few years for the hormones to reach the settled pattern of the menstrual cycle. From late teens to mid 30s, most women have a regular pattern of menstrual cycle hormones. For some women, the natural drop in oestrogen that occurs around menstruation and during the pill-free week of oral contraception can trigger. Others find that heavy, painful periods are linked to migraine. From early 40s, the menstrual cycle can become more erratic, with much more variable fluctuation in oestrogen levels. Periods themselves can be more troublesome, with more pain and heavier bleeding. All these factors can make migraine more likely. As periods lessen, so the hormonal trigger for migraine lessens, which is why many women find migraine improves after the menopause.
HRT should not be used as a treatment for migraine. However, many women notice that migraine is more likely to occur when they have bad hot flushes and night sweats. Since HRT is very effective at controlling these menopause symptoms, it can help reduce the likelihood of migraine. However, some forms of HRT can create more hormone fluctuations, triggering migraine. This is more likely to occur with tablets of HRT. We generally recommend that women with migraine who need HRT should use oestrogen patches or gel, as these maintain stable hormone levels with few fluctuations. The best dose of oestrogen is the lowest dose necessary to control flushes and sweats. This may be as little as 25mcg of oestrogen patches, or 1 pump of oestrogen gel. Try this for 6 weeks, and if flushes persist, increase to 50mcg patches, or 2 pumps of gel. Bear in mind that it can take 3 months before full benefit is achieved, so don’t increase the dose too quickly. Some women do need higher doses, up to 100mcg patches or 4 pumps of gel, but this can usually be reduced once the symptoms settle. Unless a woman has had a hysterectomy, she will also need progestogens to protect the lining of the womb from thickening in response to oestrogen. If this goes unchecked, it can lead to potentially cancerous many years later. Women with migraine, best tolerate progestogens when combined with oestrogen in patches, or as the Mirena intrauterine system.
The Mirena intrauterine system (ʻcoilʼ) can be used for contraception, to control heavy/painful periods, and to act as the progestogen component of HRT. One advantage is that it acts directly on the womb, with very little hormone reaching the rest of the body. This means that side effects are generally very few. Another advantage is that if a woman has a Mirena, it is easy to adjust the dose of oestrogen to suit her needs. Also, many women find that their periods become very light, or stop completely while they are using a Mirena. If migraine was linked to troublesome periods, this in itself can make migraine less likely to occur.
The usual recommendation is that the effective dose of medication used for migraine prevention should be continued for around 6 months. The dose should then be slowly reduced, which may be over 2-3 months. If migraine returns after a drop in dose, then the dose increased back up to dose that effectively controlled attacks for a further few weeks before trying a dose drop again. This helps you find the lowest effective dose to control migraine, and enables you to find out how long you actually need to stay on treatment.
Even though your periods have stopped, it can take a few years for the hormone fluctuations to completely settle. This is usually just one or two years, although some women find that they still get hot flushes and migraine ten or more years after the menopause. More often, even when hormonal triggers have settled, non-hormonal ones persist and may even increase post menopause. Chronic medical conditions, while not directly triggering migraine, will make migraine more likely to occur as they generally lower the migraine threshold. Maintaining good ‘migraine habits’ – regular meals, regular exercise, a good sleep routine, balancing triggers, and looking after your general health, are all as important after the menopause as before.
All research points to the fact that hysterectomy worsens migraine. The menstrual cycle is controlled by the brain, which sends messages to the ovaries to stimulate the production of the hormones oestrogen and progesterone. These in turn prepare the lining of the womb for a potential pregnancy. If a woman does not become pregnant, then the lining of the womb is shed at menstruation and the cycle starts over again. If the womb and ovaries are removed, the hormone cycle is disrupted and the brain hormones initially go into ʻover-driveʼ as they are not prepared for this early menopause. Migraine initially worsens but generally settles again over the subsequent couple of years. Replacement oestrogen can help lessen the symptoms following hysterectomy, particularly if the ovaries have been removed. Even when the ovaries are retained, the natural hormone cycle can be disrupted, so additional oestrogen may be helpful.
Vaginal oestrogen is useful to help control local symptoms of pain and dryness in women who have no problems with hot flushes or sweats, or who still get vaginal symptoms despite using HRT. When a woman first starts to use vaginal oestrogens, a rise in oestrogen has been measured in the blood stream. Higher levels persist for a couple of weeks and then drop back down. This rise and fall can be sufficient to trigger migraine in susceptible women. With continued use of vaginal oestrogens, usually only necessary just once or twice a week, oestrogen levels settle and are less likely to trigger migraine. On this basis, don’t be put off trying vaginal oestrogens but do be prepared for an initial increase in migraine. If migraine does not settle then an alternative treatment needs to be considered. This will depend on what the initial symptoms were. If vaginal dryness was the main problem, then a lubricating gel is a non-hormonal alternative.
This information is provided as a general guide only and is not a comprehensive overview of prescribing information. If you have any queries or concerns about your headaches or medications please discuss them with your GP or the doctor you see at the National Migraine Centre.