If you’ve been following a low-carb, ketogenic diet for some time, you might have experienced the “keto night sweats” at some point. Personally, I know the first time I followed a strict low carb keto diet, I woke up a few times in the middle of the night kicking my bedsheets off because I was soaked in sweat.
These keto night sweats are actually a fairly common occurrence for some people on a ketogenic diet and there’s a few good reasons why you might be getting them. I’ll also cover a few tricks to prevent getting night sweats on a keto diet.
What are night sweats?
Even woken up in the middle of the night feeling like you’re overheating and find the bedsheets and yourself drenched in sweat? Then you’ve experienced night sweats.
Night sweats is excessive perspiration or sweating while sleeping. While night seats can be caused by too many blankets or a heavy comforter, there may also be a medical condition causing your night sweats.
How common are night sweats?
Night sweats are fairly common even in people not following a ketogenic diet, with about 41% of patients reporting at least one episode of night sweats in the previous month to their doctor. 1
What causes night sweats?
Low blood sugar
Diabetics are usually well-aware that night sweats can be a sign of low blood sugar. For those starting a ketogenic diet, you may experience a mild decrease in blood sugar at night until your body becomes fat-adapted. On a ketogenic diet, the muscles will primarily shift from a glucose (blood sugar) dependent metabolism to relying more on fat from fatty acids. However, until this fat-adaption takes place, the muscles still will want glucose for fuel. On a very low carb diet, until this transition from glucose to fat occurs, you may experience a few nights of keto night sweats.
I found having a small amount of carbohydrates with some protein in the evening usually fixed the keto night sweat issue for me.
One of the most immediate challenges people have on a ketogenic diet is dehydration, especially if you haven’t increased your sodium intake while starting the ketogenic diet. As insulin levels drop due to the lower carbohydrate intake, the kidneys will hold onto less sodium, excreting more sodium into the urine.
Make sure you’re getting enough water to help prevent the “keto night sweats.”
For some people, your “keto night sweats” may actually be due to your medications, especially if you are a diabetic on insulin or a sulfonylurea medication like:
- Amaryl (glimepiride)
- DiaBeta, Glynase, or Micronase (glyburide or glibenclamide)
- Diabinese (chlorpropamide)
- Glucotrol (glipizide)
- Tolinase (tolazamide)
If you are diabetic, be sure to check with your doctor before starting a low-carb or ketogenic diet since you may need to have your diabetic medication dose changed on a frequent basis.
Hormones (Estrogen and Progesterone in women)
If you’re a middle-aged female experiencing night sweats, you might be perimenopause. Changes in estrogen and progesterone can cause night sweats in women as these hormone levels change due to menopause.
Hormones (Testosterone in men)
Men can also suffer from (non-keto related) night sweated due to low testosterone levels. So if you are a male and experiencing continued night sweats as well as other low testosterone symptoms such as low libido and general fatigue, then it may make sense to talk to your doctor about checking your testosterone levels.
Thyroid and keto
If you have hypothyroidism and take thyroid medications, your “keto night sweats” might actually mean that you need to adjust your thyroid medications. While it’s not common, I have seen patients that needed less thyroid replacement after going on a ketogenic diet. A 2002 study by Dr Jeff Volek found that a low-carb ketogenic diet improved T4 levels in 12 patients 2
If you’re hypothyroid and still having night sweat issues after you’ve been on keto for several months, have your doctor check your thyroid labs since it might require lowering your thyroid dose.
Sleeping environment is an often-overlooked factor in keto night sweats. As we sleep, our core temperature drops and you’ll find that you’ll sleep better in a bedroom that is cooler. I’ve found that people that sleep in a cooler room, with either a window left open or with the air-conditioning on during the summer sleep more comfortably than those that don’t keep the bedroom cooler.
Other medical issues causing night sweats
In most cases, the “keto night sweats” are a temporary issue that should improve once you’ve been on the ketogenic diet for several weeks. If you are continuing to have night sweats after several weeks of starting a ketogenic diet, be sure to let your doctor know about your symptoms. While its rare, certain cancers can also present with a complaint of night sweats.
If you are having problems getting into ketosis, read our How to Get Into Ketosis Tips article.
Need more info about how to start a ketogenic diet? Then check out our Ketogenic Guide for Beginners guide.