salt craving - anyone else experienced this?

Possibly a rather odd question to pose to the group- has anyone else noticed  a craving for salt?

As many of you know, my husband was diagnosed with a GBM4 in Sept 2020. In the weeks/months before his diagnosis, I had noticed that his craving for salt had increased. However at the time I was thinking "it's summer and he's been out running and he's been sweating so his body probably needs more salt."

After his diagnosis and probably right through till he went through his 6 weeks of chemo/radiotherapy, the salt craving continued then it seemed to ease off. 

Now though its back. He actually commented this evening that he'd been looking forward to dinner so that he could get some salt. It was chicken satay and rice and was actually quite salty without adding any extra as I'd put some salted peanuts through the sauce.

His mum passed away 28 years ago with a primary brain tumour. She died within a few days of her tumour being biopsied so we never got the full pathology and have no way of knowing if it was the same kind of tumour or not. Thinking back to the weeks before her illness, there were no signs of anything being wrong but she too craved salt. Co-incidence?

Curious to know if anyone else has noticed this.