Hot Flushes and Seasonal Change

hot flushes Mar 10, 2024

Did you know there may be a link between menopausal symptoms like hot flushes and seasonal change? Scrolling through Pubmed this study jumped out at me and I found it so interesting that I knew I had to share it. The study - Monthly variations of hot flushes, night sweats and trouble sleeping: Effect of season and proximity to the final menstrual period in the swan menstrual calendar substudy. This was published in the Menopause Journal in 2020.


In this study, 955 women logged their menstrual cycle and symptoms for 10 years, the researchers then went back and looked for patterns. I want to point out that 3302 women started this study but the end analysis was only performed on the women who completed their menstrual cycle logs and had a natural menopause in that 10-year window. The great thing about this kind of study is that the women didn’t know when their last menstrual cycle was going to be, they just kept logging their symptoms and we have the gift of hindsight to then go back and look at what was happening at that point in time.


This study found that approximately 20% of women started experiencing hot flushes 5-8 years before their last menstrual cycle. And that increased to 48% 4 years out from the last menstrual cycle this again increased to around 60% of women in the final 12 months leading up to their last menstrual cycle. Symptoms slowly decline after this point. Night sweats were less common than hot flushes starting at 30% and peaking in their final year to around 40% of the women studied. Sleeping issues were more stable with about 40% of women experiencing sleeplessness, with no significant increase with proximity to their last menstrual cycle.


This study found a peak in hot flashes in July and a low in January. The female participants were almost 70% more likely to experience these symptoms at this peak time than at any other time of the year. I want to point out this is a North American paper. July is their summer solstice and January is their winter one. This peak increase in symptoms is massive.

What was interesting is that night sweats peaked in June, a month earlier, and that women are 50% more likely to experience night sweats at this time of the year.

When it comes to sleep issues, this also peaked in July with hot flushes but with a lower 24% increase at this time.


So we have discovered women experience a peak in symptoms not only as they approach their last menstrual cycle but also inline with their summer time.


In the clinic, I have seen this worsening of symptoms with summer but this is the only research I’ve seen on this topic and the % of change is greater than I would have estimated. So let's talk more about hot flushes.


Women experiencing vasomotor symptoms like hot flushes and night sweats have a smaller thermoneutral zone. The thermoneutral zone is the temperature range in which you feel comfortable. Your body naturally maintains its core temperature by balancing heat production and heat loss without you noticing a difference. If your temperature moves above the thermoneutral range you feel hot and start sweating, if it goes below this threshold you start shivering. The narrower your symptom-free range is the more prone to flushing and shivering you are, hence the jacket on, jacket off syndrome of menopause.


Some things help expand this range and there are other things that narrow this range. Some examples of narrowing include stress and anxiety, these make you prone to feeling hot and sweaty even though the temperature of the room hasn’t changed, it's your stress hormones that have reduced your ability to regulate your body’s temperature.


Serotonin - your happy hormone works in opposition to your stress hormones, it can help widen your thermoneutral zone and prevent hot flushes. It is also involved in regulating mood, sleep, libido, memory, and digestion. The problem here is that estrogen positively influences serotonin and when your estrogen levels drop so can your serotonin levels, narrowing your thermoneutral zone and increasing your chances of symptoms. This is where stress management techniques can play a role, remember I said serotonin works in opposition to stress hormones, so if you used lifestyle techniques like exercise, bodywork, breathe work, and meditation to lower stress hormones in the first place your small amount of serotonin goes further as there are less stress hormones present.


Getting back to the research, the study I found referred to another study that found that women living in locations with colder average temperatures but greater temperature variation throughout the year experienced more hot flushes, and the discussion came back to the thermoneutral zone. Humans are great at adapting to the average weather conditions in your home environment, but the thermoneutral zone is only a few degrees, when the external temperature greatly fluctuates the thermoneutral zone challenges everyone but particularly peri-menopausal women who have more fragile, narrower ranges.


This result is also true for locations with the greatest daylight hour variation. They believe Melatonin may play a role here. Melatonin is your sleep hormone, with longer colder winter nights, you have a greater production of melatonin. Melatonin regulates your circadian rhythm and works in opposition to the stress hormone cortisol. More melatonin, less stress hormones better temperature regulation during winter, as your daylight hours increase this ratio changes to more cortisol and less melatonin. The greater this seasonal change the more at risk peri-menopausal women are of experiencing symptoms.


If you live in a location with huge fluctuations in daylight hours and temperature you are more at risk of seasonal changes in the amount of symptoms you are experiencing. Therefore it's more important to start working on factors that help you maintain or increase your thermoneutral zone NOW. For my northern hemisphere friends now really is the time to take action before the hotter months arrive, for my southern hemisphere friends you may have passed your annual symptom peak but know that symptom frequency and intensity increase the closer to your last menstrual period you are, so you are not off the hook, now is also your time to take action.


So what kind of action should you be considering now? Moving locations is not an action step I want you to take, but maybe reconsidering your holiday destination of choice, may make your break more relaxing.

With your home is there anything you can do to better regulate the temperature or at least reduce extreme temperature differences? This is especially important for your bedroom, consider how cold and dark it is at nighttime. If it's not what can you change? Can you add a fan or buy an eye mask or lighter cooling bedding?

How stressed out are you? Do you need to add more stress management tools to your life? Exercise is one of my favourite suggestions and if you are really struggling with heat or joint pain consider water activities, swimming, aqua aerobics, or even just walking in water are really great activities.


How else can you take action, can you book an appointment with someone on your healthcare team to discuss your individual needs, if you are looking for someone new to join your team I am taking on new patients. Consult


If you would to learn more about Menopause, on Tuesday 19th March at 12 noon AEST, I’m running a complimentary 30-minute webinar on understanding Menopause.  In this presentation, I will be discussing 7 factors that I have found contribute to either an easier or harder transition. Don’t worry it will be recorded in case that time doesn’t suit you, register anyway and I’ll send you the recording. Understanding Menopause


The biggest takeaway I want you to get is that menopausal symptoms can take a long time to resolve, this study was looking at 20% of women having hot flushes 8 years before their last menstrual cycle, which is far too long to be suffering, there are things you can do to improve your situation, you are worth it, please don’t put your head in the sand and try to wait it out. There will be summer peaks and winter troughs along the way but as a general rule things are likely to get worse the closer to the last menstrual bleed before they start getting better. I don’t mind what treatment options you try, my job here is done if I have encouraged you to reach out to someone today.




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