So this isn't actually about myself it is about my dad who is currently red flagged and waiting for a letter r.e tests.

I live with my partner so have been kept in the dark about this a bit by my parents as they know I am a big worryier. So about a year ago my dad got a black vertical line on his right big toenail, just like the photos I've seen when Googling toenail cancer. Over the course of 2021 this has spread to the point where his whole toenail is black but my parents didn't do anything as thought was just an infection or something! So about 2 weeks ago he went to his GP and they've red flagged him to go for tests but he still hasn't had a letter. They only told me about all this last week.

But now in the past couple of weeks the toenail next to his big one has this exact same vertical line down it. I never saw the first one as have only seen his toes in the past few days but he now has a completely black big toenail (which started as a vertical black line), and a black line on this second toenail which the doctors don't even know about.

No other symptoms aside from he's said hes felt tired in the past couple of weeks but could that maybe be a placebo effect / worry?

Having a read online I really cannot see what else this could be other than toenail cancer due to the black lines, I really don't know of anything else that starts like that. But the fact hes had it over a year and that its now spread to this 2nd toe is worrying me badly. He should be due his letter any time now but by the time he's had the tests and waited for the results it could be another few weeks of worrying yet.