Hi JC,

I often get really bad night sweats, I totally get what you mean about it being like being in a swimming pool!  I had these long before I had breast cancer and I'm not menopausal, I've never found a cause for them and I just get on with it, much as the lack of sleep is tiring obviously.  There are some things we go through which, because they aren't life threatening or don't seem to be as serious as other conditions, aren't really studied and so doctors don't really know what causes them.  I also get a lot of pains all over my body, but have done for a long time, have never bothered seeing my GP about them, I just assume it's something like fibromyalgia to be honest.

I'm not a qualified medic so this is just my own experience (or that of people I know, or through volunteering with some medical charities) on things that can cause night sweats...

Menopause is obviously a big one.  And given how complex our bodies and hormones are and also how cancer treatment can affect them I would imagine it's possible that she could have a temporary return to menopause symptoms that had previously ceased.  Not sure if that is possible but it wouldn't remotely surprise me if it was.

Some medications can cause night sweats, worth checking the slip in the packet and reading it thoroughly (or using a reputable drug website if you've ditched the bit of paper already) as she might be able to try an alternative medication.

Hypoglycaemia can cause night sweats, just as it causes sweats during the day (except we eat during the day so maintain our blood sugar levels).  A GP once told me it's impossible to have hypoglycaemia without being diabetic, but I used to do volunteer work with an endometriosis charity and met a number of women who, like me, experienced what their GPs could only put down to hypoglycaemia (exact symptoms of it and tested as low blood sugar too) but these women never experience hyperglycaemia so weren't diabetic.  Sadly hypoglycaemia on its own seems poorly understood.  It may be that eating a low glycaemic index food before bed would help.

Hormone issues are another obvious one.  My GP tested me for a phaeochromocytoma.  Came back negative but apparently the test is only 50% accurate, and even if I had one there's little they could do that isn't already being done (I'm on hypertension medication anyway).  I presume they've tested your wife for hyperthyroidism?  That's another more obvious possibly culprit.

Autonomic neuropathy is another one they think I might have, especially as they know now that I have a small lesion on my pons (your pons is the area that controls all your autonomic functions like breathing etc.)  But it doesn't need to mean a lesion or tumour of any type, it can be caused just by some nerve damage.

So even just from my basic knowledge there are many things that can cause night sweats, but there aren't always things that can be done to solve them and a lot of them can be difficult to diagnose.

I also get your concern about it being another cancer so at least she has been checked out in that regard.

I don't know the cause of my night sweats and likely never will, so all I do is try and keep my blood sugar stable through the night, and I only have a light covering when in bed.  In summer when it's warm one trick is to fold a clean sheet and put it in the freezer for a bit before going to bed.  If I feel I have a bit of a temperature (my temperature goes up at times during my menstrual cycle) I take a paracetamol to lower it a bit before going to bed.

Sorry I can't think of much else that would help.  We have a mattress and duver protector so just change the covers more often than most.

Hopefully the night sweats will clear up soon on there own.

LJ