What is this strange dark grey line curving down my wall?

[solorize]

Hi,

I moved our bed this morning and noticed a strange dark grey line
curving down the wall.(please refer to the attached image).
The line is more visible, as you can see, from the point
where our headboard normally is (approx half way down the
wall), down the the floor.

Bedroom Wall curving dark line_1.jpg (288.11 KiB) Viewed 2355 times

From what I can see it seems to be old and after poking at the line
it is not soft, but I can feed a raised & recessed difference in certain places
when I run my finger over the line.

F.Y.I.
Previously, above our bedroom we had a cold water tank in the
loft which has now been removed, when we got our heating and
boiler replaced.

Does anyone know what could have caused this line, as it is baffling me.
I would have thought if it was made by water that it would have been a
straight vertical line, rather that the curving path that is showing.

Also will it cause any health problems, with it being so close to our heads
when we are in bed if it is a old water stain?

Any advice would be appreciated.

[wine~o]

Difficult to tell from the pic but doubt it's anything to do with water...

Looks more like a small crack in the plaster that has been filled and painted.

Either that or it's a crack in space and time.... can you hear voices the other side of the wall ????

Doctor,,, Doctor.. where are you ???

[solorize]

LOL definitely cannot hear any voices, so hopefully is
like you said just a crack that has been filled.

Just seemed odd as I cant remember seeing it
when I painted the room ~10 years ago.

Guess it's time to repaint the room soon anyway
so it will give me opportunity to try and get rid of it.

Thanks for you reply

[DIY_Johnny]

You could dig a bit out and refill if you're that curious. That's what i would do but not a recommendation!