Perimenopause hot flushes: what's happening, and what actually helps
That sudden wave of heat has a real cause. Why perimenopause hot flushes happen, how long they last, seven things that help, and the treatments that work.
It starts in your chest and climbs. Within seconds your face is burning, your heart is racing and you're peeling off layers while everyone around you seems perfectly comfortable. Then, just as suddenly, it's gone, and you're left damp and chilly. If it happens in a meeting or in the middle of the night, it can feel embarrassing and relentless.
Perimenopause hot flushes (called hot flashes in the US) are one of the best-known signs of the change, and one of the most treatable. This article explains what's happening in your body, how long flushes tend to last, seven practical things that help, and the treatments worth discussing with your doctor.
The short answer: hot flushes happen because changing oestrogen levels make the brain's temperature control centre oversensitive, so it reacts to tiny rises in body heat as if you're overheating. Common triggers include alcohol, caffeine, spicy food and stress. HRT is the most effective treatment, and there are non-hormonal options if HRT isn't right for you.
Why perimenopause hot flushes happen
Deep in your brain, an area called the hypothalamus works like a thermostat, keeping your body temperature within a comfortable range. Oestrogen helps keep that thermostat steady. In perimenopause, oestrogen levels rise and fall unpredictably, and the comfortable range narrows.
Now even a small rise in body temperature can set it off. Your brain responds as if you're overheating: blood vessels near the skin widen, which causes the flushing and heat, your heart speeds up, and you sweat to cool down. Once you've cooled, you may feel cold and shivery.
A flush usually lasts a few minutes. Some women have one or two a week; others have many a day. When they happen at night, they're called night sweats, and they're a common reason for broken sleep. Our guide Why you're wide awake at 3am in perimenopause covers the night-time side in detail.
Researchers now know that a group of brain cells called KNDy neurons play a key part. When oestrogen falls, these cells become overactive and disrupt the thermostat. This discovery led to a new type of non-hormonal medicine, which we cover below.
A hot flush isn't you overreacting. It's your brain's thermostat misreading the temperature, and that can be treated.
How long do hot flushes last?
Flushes often begin in perimenopause, while you're still having periods, and can continue for some years after your last period. A large long-term US study, the Study of Women's Health Across the Nation (SWAN), found they lasted around seven years in total on average, and often longer for women whose flushes started early in perimenopause.
Everyone is different. Some women have mild flushes for a year or two; a minority have them for much longer. The key message is that you don't need to wait them out. If they're affecting your sleep, work or confidence, treatment can help at any stage.
When to get checked. Hot flushes are usually a normal part of the menopause transition, but see your GP if you have night sweats alongside a fever, unexplained weight loss or feeling very unwell, as these need checking for other causes. Also see your GP if flushes come with a racing heart or shakiness at other times, which can point to an overactive thyroid. If you've had breast cancer, talk to your specialist team about treatment, as the options are different.
7 things that help with hot flushes
Small changes won't switch flushes off, but they can make them less frequent and easier to manage. Try a few and see what makes a difference for you.
1. Track your triggers. For two weeks, note each flush and what came before it. Common triggers include alcohol, caffeine, spicy food, hot drinks, stress and warm rooms. Not everyone has the same triggers, so your own notes are more useful than any list.
2. Dress in layers. Choose light, breathable fabrics such as cotton, and layers you can take off quickly. A cardigan over a vest is easier to manage than a thick jumper.
3. Keep a cooling kit to hand. A small fan, a bottle of cold water and a facial spray in your bag or on your desk can take the edge off a flush in public.
4. Cool your bedroom. Keep the room cool, use a lighter duvet or layered bedding, and keep a fan and cold water within reach. Splitting a double duvet into two lighter ones can help if you share a bed.
5. Look at alcohol and smoking. Alcohol is a common trigger for both flushes and night sweats, so try a run of alcohol-free evenings. If you smoke, stopping can help reduce flushes, and it's good for your heart and bones too.
6. Stay active. Regular exercise supports mood, sleep and heart health. Some women find hard exercise triggers a flush in the moment, so experiment with timing and keep water nearby.
7. Talk about it. Letting colleagues or family know what's happening takes away some of the embarrassment. At work, simple adjustments like a desk fan, a seat near a window or a looser uniform can help.
Treatments to talk to your doctor about
If flushes are affecting your life, there are several effective treatments. Our guide How to talk to your doctor about perimenopause will help you prepare, and a two-week flush diary gives your doctor a clear picture.
HRT. Hormone replacement therapy is the most effective treatment for hot flushes and night sweats, and UK guidance recommends it as a first option for most women. It comes as patches, gels, sprays or tablets. It has benefits and risks that depend on your age and health history, so it's a decision to make with your doctor. Our guide HRT for perimenopause in 2026: a calm look at the evidence explains the pros and cons.
Non-hormonal medicines. Fezolinetant is a newer, non-hormonal tablet that works on the KNDy brain cells. NICE recommends it for moderate to severe flushes when HRT isn't suitable, and it needs regular liver blood tests. A similar medicine, elinzanetant, is licensed in the UK but isn't yet routinely available on the NHS. Some other medicines, including certain antidepressants, are sometimes used, but they aren't usually a first choice for flushes alone.
CBT. Menopause-specific cognitive behavioural therapy is recommended by NICE for hot flushes and night sweats. It doesn't always reduce how often flushes happen, but it can make them less distressing and help with sleep. You can use it alongside HRT or instead of it.
Supplements and herbal remedies. Some women try black cohosh, soy isoflavones or other herbal products. There's some evidence they may ease flushes, but products vary, their safety is uncertain, and some interact with other medicines. Always check with a pharmacist or GP first, especially if you take other medication or have had breast cancer.
Frequently asked questions
### 1. What does a perimenopause hot flush feel like?
Most women describe a sudden wave of heat spreading through the chest, neck and face. Your skin may go red and blotchy, your heart may race, and you may sweat heavily. It usually lasts a few minutes and can be followed by feeling cold and shivery. Some women also feel anxious or on edge during a flush.
### 2. Can you get hot flushes while still having periods?
Yes. Hot flushes often start in perimenopause, while your periods are still coming, sometimes regularly. They can begin years before your last period. If you're in your forties with flushes and changing periods, perimenopause is a likely cause, and you don't need to wait for your periods to stop to get help.
### 3. What triggers hot flushes?
Common triggers include alcohol, caffeine, spicy food, hot drinks, stress, hot weather and warm rooms. Triggers vary from person to person, and some flushes happen with no obvious trigger at all. Keeping a simple diary for two weeks is the most reliable way to spot your own patterns.
### 4. What is the best treatment for hot flushes?
HRT is the most effective treatment for most women. If HRT isn't suitable, NICE recommends fezolinetant, a non-hormonal tablet, for moderate to severe flushes. Menopause-specific CBT can also help, alongside or instead of medicine. The right choice depends on your health and preferences, so talk it through with your GP.
### 5. How can I stop hot flushes at night?
Keep your bedroom cool, use light layered bedding and breathable nightwear, and keep a fan and cold water by the bed. Cutting down on alcohol in the evening often helps. If night sweats are regularly waking you, speak to your GP, as HRT and other treatments can reduce them significantly.
Your next step
Perimenopause hot flushes are common, but you don't have to put up with them. This week, start a simple flush diary: when each flush happens, how bad it is and what came before it. It will help you spot your triggers and give your GP a clear picture if you decide to talk about treatment.
If you'd like to see whether your flushes are part of a bigger pattern, take our three-minute symptom check-in. You'll get a summary to take to your appointment. And for calm, practical guidance in your inbox, join our weekly email: one letter a week, nothing you didn't ask for.
This article is general information, not personal medical advice. If you're worried about hot flushes, night sweats or any new symptoms, please speak to your GP.
There are effective hormonal and non-hormonal treatments for hot flushes. If they're affecting your life, you don't have to wait them out.
