night sweats

What Causes Night Sweats In Pregnancy?

Night sweats in pregnancy are very normal, but you may still be wondering what causes night sweats in the first place. 

It’s caused by a combination of hormones and changes to your body that make it more difficult for you to cool down at night.

Sweating is nature’s way of helping regulate your temperature. During pregnancy, your body temperature increases slightly. 

This is a natural byproduct of growing a baby. In addition, hormonal changes increase blood volume, and weight gain contributes to this small uptick.

When you start to feel warm, sweating cools you down and prevents you from overheating, which could be dangerous for you and your baby

Additionally, hormonal shifts can trigger your brain’s hypothalamus into thinking your body is even hotter than it is, which can activate more sweating than is needed. This might be why you feel like it’s 100 degrees when it’s only 75.

Most of the time, sweating during pregnancy isn’t worrisome. However, truly excessive perspiration is occasionally a symptom of something unrelated to pregnancy. If you are concerned about your sweating, consult your physician.

Night Sweats, Explained

In scientific literature, night sweats can be defined as drenching sweats during sleep that requires you to change clothes. 

But they can also refer to the less drastic nighttime hot flashes that leave you feeling stifled.

In general, night sweats are fairly common. 

We don’t have data on the prevalence of night sweats in pregnant women specifically, but a 2013 study of women revealed that 35 per cent reported having hot flashes while pregnant. But why?

Many conditions and circumstances can cause night sweats and temperature regulation issues, including a thyroid disorder, infections, and, yes — normal physiological changes that come with pregnancy. So let’s boil it down.

Causes

Between hemorrhoids, bleeding gums and acne, what isn’t to blame these days on those raging pregnancy hormones? The hormonal shifts that occur when sperm meets egg confuse the hypothalamus (the area of the brain that helps regulate body temperature), making it perceive heat even if it’s a balmy 70°F outside.

This, in turn, triggers your body’s sweating reflex — designed to cool you down when the temperature is heating up.

Other potential causes include a higher-than-usual BMI (as much as possible, try to keep your pregnancy weight gain to the amount your practitioner recommends) and, believe it or not, your baby-to-be.

By the third trimester, your little bun is heating the oven of your body as part of the growth process like never before. So while they will stay perfectly comfortable, you’ll be the one feeling the heat!

Your belly can feel like a little heater—and it is. However, all that sweat comes from changes in the whole body. These are some of the most common, sweat-inducing factors at play in a pregnant woman’s body.

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Changing Hormones

Changing hormone levels during pregnancy are responsible for many pregnancy symptoms and discomforts, including a slight rise in body temperature and the resulting increase in perspiration. 

Increased Blood Circulation

There is more blood circulating in your body during pregnancy, which can make you feel warmer. In fact, by the beginning of the third trimester, your blood volume will increase by almost 50%.

Higher Metabolism

You burn more calories and generate more heat when you’re expecting as your body is working harder, which makes sense. So you’re working for two—maintaining your body and growing a new one.

Weight Gain

It can take more effort to move around when you’re carrying extra weight, especially in the third trimester, and this extra effort generates more heat. 

Plus, carrying a baby shifts your body’s centre of gravity, which can also make your body work harder to keep its balance—and feel hotter.

Weather

You can expect to sweat even more when you spend time outdoors in hot, humid weather, as it will take more effort to cool off your pregnant body.

Physical Activity

When you’re pregnant, you may sweat more than usual when you exercise, clean the house, go on a walk, or participate in any other activity that strains your body.

Anxiety

Sweating is a natural response to stress and nervousness. As a result, you may experience excessive sweating when pregnant if you have anxiety or mood swings.

Illness

A fever from a cold, flu or other illness can also cause an increase in body temperature, which can cause more sweating. 

Hyperthyroidism

A normal increase in thyroid activity during pregnancy (in response to hormonal shifts) can cause higher body temperatures and amounts of sweat. 

However, hyperthyroidism is beyond what is considered normal. 

An overactive thyroid may speed up your heart rate and body systems, causing excessive sweating (beyond the expected increase) and other symptoms.

Medication

Sweating is a side effect of some medications. This includes certain medicines that treat nausea, which some pregnant women take to offset morning sickness

Food And Drink

Spicy foods, alcohol, and caffeine can all trigger sweating, so limiting these in your diet can help keep sweating in check. (You should avoid alcohol and avoid or limit caffeine during pregnancy anyway, and spicy foods can trigger heartburn as well as sweating.)

Low Blood Sugar

During pregnancy, your metabolism is in overdrive to give your little one all the nutrition required to grow from the size of a mere seed to a watermelon. 

That means you can be left a little depleted if you don’t consume enough calories, or equally balanced calories, throughout the day.

If this is the case, you could experience hypoglycemia or low blood sugar. And night sweats, or nocturnal hypoglycemia, can be a tell-tale sign.

While a study states that hypoglycemia is rare in pregnant women who do not have diabetes, women who have any form of diabetes or its risk factors should be aware of the possible connection to night sweats.

night sweats

What Can I Do About Excessive Sweating During Pregnancy?

There’s no magic solution when you’re sweating on overdrive — but there are many ways to feel more comfortable:

Keep hydrated. You’re losing water when you sweat a lot, which can make you feel dizzy and faint. So take a drink. What’s more, cold liquids can help your body regulate its temperature.

Always keep a bottle of cold water with you, and drink when you’re thirsty — don’t wait until your mouth feels dry. (Or put it on the back of your neck to cool you off when you get hot.) 

You’ll need to gulp down, even more when you’re working out or the weather’s warmer. 

Water is best, but milk, natural juices, iced herbal tea, and fruits and vegetables count as fluids, too (stay away from soda and sweetened drinks to avoid empty calories, which can lead to excess weight gain). 

Rule of thumb: If your urine is almost white or slightly yellow, it’s a good indication you’re hydrated.

Stay out of the sun and in air-conditioned environments. 

That goes for both night and day — fans don’t help when it’s 90°F and humid! Avoid hot spaces like saunas or hot tubs (which are always no-gos during pregnancy) too.

Avoid working out in the heat of the day. Instead, opt for walks in the early morning or evening, sign up for a class in your air-conditioned gym, or take a dip in the pool (bonus: it may also help relieve swelling in your feet and ankles, too).

Wear loose, light clothing. Layer it on so you can easily shed clothing or bundle up.

Layer your bed with blankets. Then, make it easy to make the same quick temperature adjustment at night.

Sleep on a towel. It will help absorb excess sweat while you sleep.

Avoid hot drinks and spicy foods, especially if they trigger your sweat reflex (plus that extra hot habanero sauce isn’t helping your pregnancy heartburn, either!).

Carry a handheld fan. Fanning yourself will help evaporate excess sweat in a pinch, cooling off your skin.

Use talc-free powder. A dash of powder in areas prone to friction will absorb excess moisture and prevent heat rash during pregnancy.

Can I Prevent Sweating During Pregnancy?

Well, you can try to keep your cool, but there’s not much to do about your surging hormones and weight gain. 

However, make sure you have a working air conditioner or a decent fan at home and an ice machine that cranks out cubes.

When Can I Expect The Sweating To End?

You can probably expect to be extra warm and toasty right up to and after birth. 

The sweat effect will likely dissipate gradually as your hormones start to regulate themselves — probably about the time you begin ovulating a few months post-delivery again.

After delivery, your basal temp should go back to normal. 

But anecdotally, many women say they never went back to their pre-pregnancy selves, temp-wise (good news for those of you who were always complaining about the cold!). So it’s all fine and normal!

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When Night Sweats Are Most Common During Pregnancy

Could They Be An Early Sign Of Pregnancy?

In the wee stages of pregnancy, you might have heard the rumour that night sweats or hot flashes could be a sign that you’ve got a bun in the oven.

It’s true that your basal body temperature increases during specific times of your menstrual cycle. 

This spike usually happens when your body signs your ovaries to release an egg, which is considered your fertile window — the period during which you could conceive.

It’s also entirely possible that hormone fluctuations in early pregnancy could cause you to wake up hot or downright soaked. Still, it’s always advised to lean on your trusted pregnancy test and OB to be, well, “positive.”

First Trimester To Postpartum

A 2010 longitudinal study indicated that a pregnant woman’s core body temperature registers highest during the first trimester and decreases throughout each trimester and up to 3 months postpartum.

One 2013 study, however, found that 29 per cent of women reported hot flashes after delivery. 

All this is to say that the ups and downs of pregnancy and delivery can also bring unexpected ups and downs with your temperature.

And if you’re waking up soaked during the “honeymoon” phase of pregnancy, it will likely end soon, along with those nagging first trimester fatigues.

When Pregnancy Sweating Starts And Ends? 

Increased sweating is normal throughout pregnancy and during the postpartum period. However, the first and third trimesters are when sweating is the most common and severe.

Many women start feeling sweaty very early in their pregnancies.

The changing hormones and increase in blood flow slightly raise the body temperature soon after you become pregnant, and this small increase is enough to make you feel hot—and sweat a lot more than you’re used to. 

Sometimes, it’s one of the first signs of pregnancy that a woman notices. 

Some women get relief from sweating during the second trimester. 

However, don’t be surprised if it returns in the last few months as you get closer to delivery, particularly if you happen to be waiting out your third trimester during the heat of summer. 

Additionally, research has found that around 35% of women report hot flashes during pregnancy and postpartum.2 

Postpartum sweating is also very normal. It is one of the ways your body gets rid of the extra fluid it was carrying while you were pregnant. 

Additionally, night sweats (nocturnal hyperhidrosis) due to postpartum hormonal shifts can occur while your body gets back in balance after your baby is born.

After your baby is born, you may continue to sweat for a few weeks as your hormones adjust and your body returns to its pre-pregnancy state. 

Getting Some Relief 

We know those prego mama worries can jump to the worst-case scenario in seconds. But the answer to keeping cool is often a simple fix.

Managing night sweats starts with figuring out what’s causing them. 

For most pregnant women, the occasional night sweat is considered a normal result of the body’s transitions throughout this exciting time.

However, that doesn’t mean you can’t find relief. Talk to your doctor about any new symptoms you have, including night sweats, to determine the possible cause and remedies.

In the meantime, consider modifying your sleep environment. 

Studies show that your room temperature and even pyjama choices could influence your body’s ability to cool itself while getting your Zzz’s.

Turn down your AC a few degrees, use lighter-weight bedding, and select soft cotton or more breathable fabric for your nightwear.

If you suspect a more serious medical condition or medication is causing your night sweats, or if your night sweats occur with a fever, rash, or other concerning symptom, it is especially important to contact your OB-GYN immediately.

It doesn’t have to be a sweltering, humid day to feel hot and sweaty when you’re pregnant. 

night sweats (3)

Pregnant women sweat during the cold winter months, too. Unfortunately, there isn’t much you can do about your pregnancy hormones and your body’s response, but there are effective strategies you can try to find relief.

  • Drink plenty of water or other healthy fluids to stay hydrated and replace what moisture you’re losing as you sweat.
  • Dress in light, breathable clothing made with natural fabrics, such as cotton, and avoid warm materials, such as wool.
  • Wear layers that you can remove when you begin to feel warm.
  • Take a daily bath or shower with lukewarm water to cool off and feel fresh.
  • Wear an antiperspirant. 
  • Turn on an air conditioner or fan. 
  • Stay away from foods and drinks that are known to increase body warmth and sweating.
  • Carry a handheld fan with you when you go out.
  • Carry baby wipes in your bag for a quick cool-down when you’re feeling sweaty. 
  • Splash cool water on your face or hold a damp, cool cloth on your forehead.
  • Aim to stay within your doctor’s guidelines for weight gain, as extra pounds can make you feel warmer.

When The Weather Is Hot

You may need extra cooling techniques when you’re facing hot and humid weather during pregnancy.

  • Try to stay out of the direct sun, especially during the hottest part of the day; when possible, seek out shade.
  • Wear sunscreen when you go outside.
  • Plan your outings in the morning or evening, when temperatures are cooler.
  • Exercise indoors in an air-conditioned space or during the cooler parts of the day if you’re outdoors.
  • Spend the day in places with air conditioning, such as at the mall or a movie theatre.
  • Go for a swim.

At Night

Sleeping while pregnant, particularly in the third trimester, is a challenge for any expectant mom, especially those who experience night sweats. 

Night sweats are more than just feeling hot and sweaty at night. They can be drenching sweats that can soak through pyjamas and sheets.

Night sweats are not only uncomfortable but tend to interfere with your sleep, causing tossing and turning, waking you in the night, and requiring clothing and bedding changes. 

To help you get through night sweats during pregnancy and the postpartum period:

  • Wear light, loose-fitting pyjamas.
  • Use lightweight bed sheets.
  • Change to a lighter or thinner comforter, blanket, or duvet. You can also layer your sheets and blankets so you can use only what you need during the night. 
  • Turn up the air conditioner to make the room cooler.
  • If you have one, turn on the ceiling fan or buy or borrow a floor fan for your bedroom. 
  • If possible, open a window to allow fresh, cool air into your room.
  • Sleep on a towel or multiple towels to absorb sweat and protect your sheets. It’s easier to wash the towels than to change and wash the sheets every day—or during the middle of the night.  
  • Drink plenty of healthy fluids during the day to replace what you’re losing through sweating at night.

When To Call Your Doctor

Even though sweating and night sweats are common in pregnancy, it’s a good idea to discuss all symptoms with your doctor during your prenatal appointments. Then, your doctor or midwife can confirm whether symptoms are pregnancy-related or something else.

Your healthcare provider can also answer any questions you have, advise you on ways to find relief, and follow up with you to monitor that your body (and perspiration rate) returns to its pre-pregnancy state after you’ve had your baby. You should call your doctor immediately if:

  • You are itchy all over, especially if you do not have a rash.
  • Your temperature exceeds 100.2 degrees F. 
  • You have symptoms of dehydration or illness.
  • You feel dizzy or faint.
  • You are very uncomfortable.
  • Sweating does not get better by six weeks after your baby is born.
  • Do you have any serious questions or concerns?

Conclusion

Sweating is a common discomfort of pregnancy. You might routinely feel flushed, have hot flashes, or wake up in a puddle of sweat. All this sweat can be embarrassing, uncomfortable, and inconvenient, but it’s a normal part of pregnancy and usually not a cause for concern. 

While you can’t control your hormones and your body temperature, you can usually find some relief. Thankfully, serious complications from sweating are rare. As long as you stay hydrated and try your best to keep your skin cool and dry, you should be able to prevent issues such as overheating, dehydration, and heat rash. By and large, sweating is a good sign that your pregnant body is working as it should be—and that’s something to glow about.

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