Keto Night Sweats Cause + Quick Fixes for Hot Flash & Keto Flu

Keto (Low Carb) | Written by Nathan Petitpas | Updated on 8 April 2023

An Asian woman is sitting in her bed with a blue light on, white pillow cases, a white headboard with books on it, and a brown comforter looking miserable due to waking up from keto night sweats or hot and cold flashes and a bedside night lamp to her right and on a night stand with books within it.

Keto night sweats are often an unfortunate and uncomfortable “side effect” of the keto diet, usually accompanied by other less-than-ideal symptoms including irritability, hunger, and fatigue that have collectively been dubbed the “keto flu.”6 

When starting keto, sweating at night happens much more frequently than dieters would like and this is often combined with several other discomforts.

Such night sweats, hot flashes–and day sweats too, for that matter–can be caused by sugar withdrawals, nocturnal hypoglycemia, dehydration, and other factors that we’ll explain further below; but rest assured that the sweating should go away in time and we’ll also provide quick fixes for those who are looking for an immediate solution. 

Can Ketosis Cause Night Sweats? Are My Hot and Cold Sweats at Night From Keto?

Keto and night sweats go together a little too well and too often; whether one experiences hot sweats or cold sweats throughout the night, this can often be chalked up to the keto low carb diet and is classified as keto flu night sweats. 

Somebody following weight loss diets for beginners may never have experienced keto night sweats before and, more broadly, may have never dealt with night sweats at all up to this point.1

For those in such a situation who are at a loss for what causes this excessive sweating, they likely have the burning question of “does keto cause night sweats?” Yes, the keto diet can contribute to this uncomfortable state of waking up soaking wet and drenched in sweat. 

A muscular man wearing a tank top with sweat visible on his chest in black and white.

Source: un-perfekt from Pixabay7

The causes are fairly broad, but one main reason for this is that the body is losing some water that had been retained in the body when consuming carbs.

Carbohydrates drastically promote increased water storage through glycogen (up to 4g of water per carb) within the body, so when those carbs are no longer available or being consumed in the form of food or drinks, the body has no choice but to release some of that extra water in the form of sweat. 

Another reason for keto night sweats is that when following a low carb diet, the body starts burning ketones–molecules formed from fat when blood glucose is low–to function properly.

The action of creating ketones from fat itself raises the temperature of the body and makes sweating more likely and more common, whether in the day or night

It will likely come as some relief to learn that the keto flu, night sweats, and other symptoms should be temporary and usually last a few weeks to a month until the body adapts to this new way of functioning. 

Unfortunately it might get a bit worse before it gets better, as those “other symptoms” of the keto flu that we mentioned can and often do include one or more of the following: 

  • Heart Palpitations
  • Nausea
  • Vomiting
  • Constipation
  • Bloating
  • Diarrhea
  • Fatigue
  • Restlessness
  • Irritability
  • Headaches
  • Dizziness
  • Bad Breath
  • Muscle Cramps
  • Joint Pain
  • Insomnia
  • Rashes

How few carbs are consumed, how many carbs a person was consuming before going into ketosis, and the level of carb reduction sensitivity from person to person can all impact how severely these symptoms of keto flu are experienced. The more carbs cut and the more drastic the change, the worse one is likely to feel. 

Since carbs are the body’s primary energy source, someone beginning keto should expect to feel much more tired as their body reacts to the sudden lack.

Sleepiness and the other symptoms often begin 2-7 days after jumping into keto restrictions and tend to last from several days to several weeks, but should not persist for longer than a month at most.

The amount of weight one can expect to lose on the keto diet depends on many variables, but it’s wise to keep in mind that it’s mostly water weight–not fat–that is lost early on due to the extra sweating, so be realistic about weight loss goals and expectations.

Cause of Keto Night Sweats & Reasons Keto and Night Sweats Go Hand in Hand 

Night sweats are rather common whether diet-related or not, but sweating can be highly exacerbated by the new restrictions and changes on keto. 

Many people wonder and even research if you can be in ketosis and still not lose weight, but beware of going too far in the other direction as well and thinking that the rate of weight loss in the first few days or weeks of the keto diet is sustainable.

Keto night sweats tend to really expedite rapid weight loss right away but this is mostly water weight and weight loss may plateau temporarily or slow after this initial stage.

Hot flashes are also a common discomfort on keto, and can be caused by the diuretic effect of ketosis in which one urinates more frequently and loses both water and electrolytes.

These can also be brought on by the body shifting from burning glucose to ketones and having trouble adapting quickly to use the ketones efficiently. 

Luckily, this should stop after a few weeks. Other than an electrolyte imbalance and ketone burning, keto hot flashes may be caused by  few other factors which are expanded upon below.

Nocturnal Hypoglycemia

Nocturnal hypoglycemia occurs when one’s blood glucose drops below 70 mg/dl during the night, often while one is asleep. Hypoglycemia in Type I Diabetes is quite common at night, but can happen to anyone and is exacerbated by the keto diet due to having so few carbs and sugars.2 

Hypoglycemia can happen at any time, day or night, but a majority of episodes or cases happen during sleep. 

Signs or symptoms of moderate to severe nocturnal hypoglycemia include:

  • Frequent nightmares
  • Feeling extra tired even after sleeping
  • Excessive sweating throughout the night
  • Waking up in damp or soaked clothes or bedding
  • Waking up with a headache
  • Confusion
  • Slurred speech or difficulty speaking
  • Nervousness, shakiness or jitters

Diabetics have had to experience the impact of hypoglycemia on quality of life for much longer than the few weeks of keto flu and studies on diabetics have given us some ways to prevent or decrease the severity of hypoglycemia, including eating frequent small meals throughout the day, getting plenty of protein and fat (perfect for keto), and consuming sufficient fiber and nutrients.3

Since hypoglycemia is proven to cause heightened stress, these may be some helpful tips to try if one is suffering from any of the above symptoms. 

Sugar Withdrawals

Prior to starting the keto diet, many people eat foods that are highly processed with added fats, sugar alcohols, and refined carbs. Binging on sugar can not only cause changes in brain function and development that reflect that of a drug or opioid addict, but that the addictive qualities themselves carry over too. 

Therefore, withdrawing from sugar by completely eliminating it from one’s diet or vastly decreasing consumption causes similar symptoms to opiate withdrawals. One of the major crossover symptoms is excessive sweating through the night. 

Dehydration

Hot and cold sweats at night can easily lead to dehydration especially because of the loss of electrolytes at the beginning of keto and the body reeling from the sudden changes. 

The body also stores hundreds of grams of carbs as glycogen and each gram can store up to 4 grams of water as well, so when these stores are suddenly restricted or depleted, the body utilizes the previously stored glycogen and the held water is released as sweat and/or urine.

Electrolytes are lost through the same process, so the body cannot maintain fluid as well. Electrolyte imbalance or lack can also contribute to dehydration. 

Adding some salt to water or food at the beginning of keto may lessen these symptoms. Using an electrolyte supplement might be wise too; try finding one with plenty of potassium and, most importantly, be sure to drink plenty of water.

You might find hydration powders like Liquid IV helpful, but if you’re wondering is Liquid IV keto?”, unfortunately it’s not as it is made with dextrose and carbs.

Other Factors 

When it comes to night sweats, keto can even exacerbate other factors that can also cause extreme sweating. Those who have any of these other factors going on should be especially cautious when adjusting to a low carb diet.

Certain Medications: Medications (including many that are insulin-related, pain relievers, and antidepressants) that commonly cause night sweats include:

  • Amaryl (glimepiride)
  • Bupropion (Wellbutrin)
  • DiaBeta, Glynase, or Micronase (glyburide or glibenclamide)
  • Diabinese (chlorpropamide)
  • Escitalopram (Lexapro)
  • Glucotrol (glipizide)
  • NSAID pain relievers
  • Opioids
  • Prednisone
  • Sertraline (Zoloft)
  • Tolinase (tolazamide)
  • Tolbutamide
  • Triptans

Note: Diabetics should consult a doctor before trying any low carb diet as medication or eating habits may need to be altered due to the added vulnerability to some symptoms.

Type I Diabetes: For those with diabetes, night sweats, dizziness, confusion, and other symptoms of low blood sugar are all too familiar.

With so many precautions already needed, diabetics should be very careful of trying any low carb diet and should come up with a meal plan or options with their doctor prior to trying keto or anything similar.

Thyroid Issues: Thyroid issues–especially hypothyroidism–can be linked to night sweats, and a commonly used hypothyroidism medication called “levothyroxine” is a common culprit of not only night sweats, but hot flashes and overheating in general.

Those on thyroid medications should talk to their doctor if “keto night sweats” persist because it could be medication-related instead.

Hormones: Estrogen, progesterone, and testosterone imbalances can all cause night sweats and may cause heightened sweating when someone is on keto. This is especially true during perimenopause and menopause.

How To Alleviate Keto Sweats at Night (Keto Night Sweats Solutions)

While potential health benefits of the keto diet abound, keto night sweats and other frustrating symptoms can range from putting a slight damper on daily life to causing one to be completely miserable during the first few weeks of following the keto diet.4

This can certainly derail motivation and willpower, so we have some potential solutions for those seeking alleviation of keto flu symptoms:

A girl lying on a bed with her knees bent, wearing a bracelet on her wrist.

Source: Ichigo121212 from Pixabay8

  • Keep exercise light (brief description of why this helps)
  • Eat high-quality fats 
  • Focus on nutrition 
  • Eat plenty of vegetables
  • Drink cold water
  • Take a cool shower before bed
  • Eat small, frequent meals 
  • Sleep in a cool environment 
  • Wear loose clothing to bed
  • Avoid triggers such as caffeine and spicy foods
  • Don’t smoke or drink alcohol
  • Replenish electrolytes
  • Use breathable sheets and blankets
  • Relax and unwind before bed 
  • Try flaxseed, black cohosh, or evening primrose oil to reduce hot flashes 

Whether or not these help provide some relief, consult a doctor if excessive sweating or any other concerning symptoms persist for longer than a month to ensure it’s not being caused by something else.

Dietary Changes Can Cause Night Sweats; Keto Is No Exception

Although often collectively called the “keto flu”, the aforementioned symptoms are actually quite common amongst those starting weight loss diets or decreasing their carbs even as part of intuitive eating for weight loss.

It would be more aptly named the low carb flu since this is a well-known phenomenon in the beginning stage of popular and trending diets to the extent that some refer to the similarly dubbed whole30 night sweats and intermittent fasting night sweats.

Night sweats when dieting are likely caused by similar reasons across the board: lower carb intake, nocturnal hypoglycemia, dehydration and withdrawals from sugar.

However, the keto diet can bring more severe versions of these symptoms or worse sweating due to the emphasis on strict carb restriction. 

Are Night Sweats With Odor Normal With Keto? 

While any sweat likely has some odor, keto night sweats are known to have a distinct scent; some describe it as more sweet or even fruity, while others compare the smell to that of acetone. But are night sweats with odor normal with keto?

Strangely enough, keto sweats at night actually should have a noticeable smell–this signifies that the body has begun burning ketones and is starting to adjust to the carb restrictions. This odor isn’t just in sweat, but might be noticed on one’s breath as well if they recently started the keto diet. 

Don’t fret; this unique scent should fade away within a couple of weeks when the body has had a chance to adapt, but there are some options for those who want to minimize the smell in the meantime.

How To Prevent Keto Body Odor & Bad Breath

The keto-induced body odor and bad breath are about as common as night sweats during keto, but that doesn’t mean the smell is enjoyable or unbothersome. For those who cannot tolerate the odor, try the following:

A clear glass filled with water and ice, with a bamboo straw sticking out from the top.

Source: abillion from Unsplash9

  • Drink plenty of water
  • Maintain good oral health
  • Shower or bathe regularly 
  • Wash sheets and pillowcases often
  • Be patient 

A low carb keto diet can reduce cardiovascular risk factors and offers many other health benefits, but hot and cold sweats on the ketogenic diet can make for an odorous and uncomfortable time while waiting out the first few days or weeks of the diet.5

Remember that keto night sweats are very common as the body reacts to functioning on fewer carbs and utilizing ketones more efficiently, but this is temporary and there are many options for alleviating the excessive sweating and odor until this keto flu symptom is over.

Frequently Asked Questions

Does Keto Cause Night Sweats in Every Keto Dieter?

For those wondering if ketosis can cause night sweats in all keto dieters, the answer is no; this is a common occurrence as people adjust to a low carb diet, but not everyone will experience it.

What’s the Best Way To Reduce Keto Hot and Cold Sweats at Night?

The best way to reduce keto sweating at night is to ensure proper hydration and a calm, cool sleeping environment.


References

1National Cancer Institute. (2023). night sweats. National Cancer Institute. Retrieved February 3, 2023, from <https://www.cancer.gov/publications/dictionaries/cancer-terms/def/night-sweats>

2Maclean, R., Jacob, P., Choudhary, P., Heller, S., Toschi, E., Kariyawasam, D., Brooks, A., Kendall, M., Zoysa, N., Gonder-Frederick, L., & Amiel, S. (2022, March). Hypoglycemia Subtypes in Type 1 Diabetes: An Exploration of the Hypoglycemia Fear Survey-II. National Institute of Health. Retrieved February 3, 2023, from <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8918257/>

3Coolen, M., Broadley, M., Hendrieckx, C., Chatwin, H., Clowes, M., Heller, S., Galan, B., Speight, J., Pouwer, F., & Abdelkreem, E. (2021). The impact of hypoglycemia on quality of life and related outcomes in children and adolescents with type 1 diabetes: A systematic review. National Institute of Health. Retrieved February 3, 2023, from <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8638919/>

4Dowis, K., & Banga, S. (2021, May). The Potential Health Benefits of the Ketogenic Diet: A Narrative Review. National Institute of Health. Retrieved February 3, 2023, from <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8153354/>

5Luo, W., Zhang, J., Xu, D., Zhou, Y., Qu, Z., Yang, Q., & Lv, Q. (2022). Low carbohydrate ketogenic diets reduce cardiovascular risk factor levels in obese or overweight patients with T2DM: A meta-analysis of randomized controlled trials. National Institute of Health. Retrieved February 3, 2023, from <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9792675/>

6cottonbro studio. “A Lonely Woman Sitting on a Bed.” Canva. Accessed 9 April 2023. <https://www.canva.com/photos/MAEVksAfKNo-a-lonely-woman-sitting-on-a-bed/>

7un-perfekt. “Free Image on Pixabay – Black-And-White, Human, Chest, Man.” Pixabay, 5 August 2018. Accessed 9 April 2023. <https://pixabay.com/photos/black-and-white-human-chest-man-3581502/>

8Ichigo121212. “Light Photoshoot – Free photo on Pixabay.” Pixabay, 28 October 2014. Accessed 9 April 2023. <https://pixabay.com/photos/light-photoshoot-bed-506120/>

9abillion. “clear drinking glass with white straw photo – Free Plant-based Image on Unsplash.” Unsplash, 12 October 2020. Accessed 9 April 2023. <https://unsplash.com/photos/6vkvgAMpqpo>

About the Author

Nathan Petitpas

Nathan has been a fitness enthusiast for the past 12 years and jumps between several types of training such as bodybuilding, powerlifting, cycling, gymnastics, and backcountry hiking. Due to the varying caloric needs of numerous sports, he has cycled between all types of diets and currently eats a whole food diet. In addition, Nathan lives with several injuries such as hip impingement, spondylolisthesis, and scoliosis, so he underwent self-rehabilitation and no longer lives with debilitating pain.