What Is a Hot Flash?
Hot flashes are the most common symptom of perimenopause and menopause, which is the natural time when your ovaries stop releasing eggs and your period stops. Doctors refer to hot flashes as vasomotor symptoms (VMS). During a hot flash, you have a feeling of intense heat in your face, neck, and chest. You may also sweat large amounts and feel chilly afterward.
More than two-thirds of people assigned female at birth (AFAB) in North America who are in perimenopause or menopause have hot flashes. They can also affect those whose ovaries don't release enough estrogen either due to chemotherapy or because their ovaries have been removed during a hysterectomy.
What Does a Hot Flash Feel Like?
Hot flashes can be different for everyone. Some people may not have symptoms that bother them, while other people have symptoms that affect their daily lives. However, common symptoms may include:
- Feelings of intense, internal heat
- A lot of sweating (When it happens at night, it's called night sweats, and it may wake you up.)
- Flushing (skin becomes hot and red), especially in the face, neck, and chest
- Chills after the hot flash is over due to excessive loss of body heat
- Increased heart rate of about 7-15 beats per minute
- Feelings of anxiety
Hot Flash Causes
During a hot flash, your core body temperature and skin temperature increase, generally in your fingers, arms, chest, abdomen, back, and legs. Blood flow also increases in these areas, which can make you sweat more. In some people, metabolic rate will also increase, which may cause your heart rate to increase. Metabolic rate is the number of calories you burn as you go about your day-to-day living.
Hot flashes during periods
Some people get hot flashes as part of their normal premenstrual syndrome (PMS) symptoms. Changes in your hormone levels around the time of your period can change the way your body regulates your body temperature. This can lead to hot flashes or night sweats.
This may start happening as you enter perimenopause, which is the time when your body goes through the changes that lead to menopause (when your period stops). Perimenopause generally lasts about 3-4 years, but it can last as long as 10 years. So, many people AFAB will start perimenopause in their 40s, or even their 30s.
If you've entered perimenopause, your period will also likely become irregular. Perimenopause may also cause changes in menstrual bleeding. It can result in periods that are lighter or heavier, last longer, or come closer together. You may also notice spotting between periods.
Pregnancy hot flashes
Having hot flashes and night sweats during pregnancy is common. In one study, about 35% of pregnant people said they had hot flashes at some point while pregnant. This is probably due to hormone changes your body goes through during pregnancy. It may be more common during your first trimester (weeks 1-14) and third trimester (weeks 27 to childbirth).
Just because you have hot flashes doesn't mean you're necessarily in perimenopause or menopause. Some medical conditions and medicines may also cause hot flashes or night sweats. But, if a medical condition is causing your hot flashes, you'll usually have other symptoms, too.
Medical conditions or medicines that can cause hot flashes include:
- Viral infections, such as the cold, flu, COVID-19, or HIV
- Bacterial infections, such as tuberculosis, endocarditis (inflammation of your heart), or osteomyelitis (inflammation of your bone or bone marrow)
- Hormonal disorders, such as an overactive thyroid, endocrine tumors, or diabetes
- Substance abuse of alcohol, heroin, or cocaine
- Neurologic disorders, such as autonomic dysreflexia, autonomic neuropathy (damage to the nerves that control your heart rate, blood pressure, respiration, digestion, and sexual arousal), syringomyelia (a cyst in your spinal cord), and stroke
- Mood disorders, such as panic disorder or anxiety
- Sleep disorders, such as obstructive sleep apnea
- Digestive disorders, such as gastroesophageal reflux disease (GERD)
- Some cancers, especially leukemia and lymphoma
- Cancer medicine, such as aromatase inhibitors, tamoxifen, opioids, and steroids
- Other medicines, such as antidepressants, diabetes medicine, steroids, acetaminophen, aspirin, and high blood pressure medicines
Hot Flash Triggers
Things that can trigger a hot flash include:
- Hot weather, heated rooms, or getting overheated by an activity
- Spicy foods
- Tight clothes
Why are hot flashes worse at night?
Hot flashes at night can cause drenching sweat that soaks through your night clothes, waking you up and preventing you from getting back to sleep. This is probably why hot flashes seem worse at night. Your body temperature usually drops a bit at night so you can sleep. But, hormone changes that affect your body temperature may be more noticeable at night, especially if it wakes you up to a drenching, cold sweat.
How Long Do Hot Flashes Last?
Hot flashes generally last 1-5 minutes, although some episodes can last an hour.
In terms of duration of symptoms, most people get hot flashes for about 4 years. You may only have them for a while during perimenopause, or you may continue to have them after your period stops. A few people may have them for the rest of their lives, but they generally become less frequent or less intense as time goes on.
How to Stop Hot Flashes
Hot flashes will usually go away eventually without any treatment. However, in the meantime, they can really disrupt your life. Small lifestyle changes may help give you relief from hot flashes. Some self-care options that can help you manage your hot flashes include:
Don't smoke or use tobacco products. People who smoke or use tobacco products may have more hot flashes than people who don't.
Exercise regularly. Sedentary people may have hot flashes more often than people who exercise regularly. However, do check in with yourself while you exercise, as overheating can trigger a hot flash. Exercise in a cool room if you think this may be a problem for you.
Lose weight. If you're carrying extra body weight, it can make your hot flashes worse.
Avoid spicy foods, caffeinated drinks, and alcohol. These can all trigger hot flashes.
Keep cool. Dress in layers so you can take clothes off when you're too warm. Open windows and use a fan or stay in the air conditioning as much as possible. Sip cold drinks when you're feeling too warm.
Practice mind-body therapies, such as:
- Mindfulness meditation
- Cognitive behavioral therapy (CBT)
- Deep breathing
- Guided imagery
Try some natural remedies.
Nonprescription, herbal, and over-the-counter therapies may help some people manage their symptoms. Botanicals and herbs may have side effects or change how other medications work, so ask your doctor before you add any new supplements to your health care routine. Some supplements that may help with your symptoms include:
- Plant or soy estrogens (although it may be more helpful to add these foods to your diet than to take supplements)
- Black cohosh
- Evening primrose oil
- Dong quai
- Wild yam
- Vitamin E
Hot Flash Treatments
If lifestyle changes and natural remedies aren't easing your hot flashes, talk to your doctor about taking medicine, such as hormone replacement therapy.
Doctors usually prescribe estrogen to treat hot flashes. It may also help other menopause symptoms, such as vaginal dryness or mood disorders. But this may not be a good option for you if you are at risk of breast or endometrial cancer, heart disease, stroke, or blood clots.
If you've had a hysterectomy, you may be able to take estrogen alone, but if you have a uterus, you will likely need to take progesterone and estrogen to avoid increasing your risk of cancer in the lining of your uterus (endometrial cancer). Your doctor will adjust your dose to the minimum amount required to ease your symptoms. They will also recommend hormone replacement only as long as it is helping your symptoms and not increasing your risk of heart disease, stroke, or blood clots.
If you can't take oral progesterone because the side effects are uncomfortable, you can try a combination drug containing bazedoxifene plus conjugated estrogens called Duavee.
Other nonhormone treatments that may help you manage hot flashes include:
Selective serotonin reuptake inhibitor (SSRI) antidepressants, such as:
- Citalopram (Celexa)
- Desvenlafaxine (Pristiq)
- Escitalopram (Lexapro)
- Fluoxetine (Prozac)
- Paroxetine (Paxil, Pexeva), including a low-dose form (Brisdelle) that is FDA-approved to treat hot flashes
- Venlafaxine (Effexor)
Other prescription medicines that are used "off-label" (which means that they aren't FDA-approved for hot flashes but are used because they're effective) include:
- Clonidine (Catapres, Kapvay), a high-blood pressure medicine
- Fezolinetant (Veozah), a medicine that acts on brain chemicals that help you regulate your body temperature
- Gabapentin (Neurontin, Gralise), an anti-seizure medicine
- Oxybutynin (Ditropan XL, Oxytrol), an overactive bladder medicine
- Pregabalin (Lyrica), another anti-seizure medicine
Hot Flash Prevention
There’s nothing you can do to completely prevent hot flashes around menopause. But you can stay away from triggers that may make them more frequent or more severe. Common ones include:
- Spicy foods
- Tight clothing
- Cigarette smoke
Hot Flash FAQs
At what age do hot flashes start?
Everyone is different, so it's hard to give a precise age for any person. Most people AFAB will start perimenopause in their late 40s to early 50s. So, this is generally when hot flashes start for most people.
Are there foods that can help with my hot flashes?
Plant estrogens may have weak estrogen-like effects on your body, which can help with your symptoms. This may be why people AFAB who grew up in cultures where vegetarian diets are common say they get fewer hot flashes. Some foods that have plant estrogens include:
- Soybeans, tempeh, and tofu
- Ground flaxseeds
- Whole grains
- Red clover
How many hot flashes a day is normal?
Everyone's body is different, but according to research, most people say they have about four to five per day.