Hello yesterday I noticed a black dot under my middle fingernail towards the top and it's really worrying me as I'm only 18 and I don't want it to be anything serious
Marks under the nail can be caused by several things - trauma (have you banged your finger?), fungal infection, a splinter hemorragh or subungal melanoma. This type of melanoma is not common, it only accounts for 1% of melanoma cases. It usually presents as a dark line that runs from the cuticle to the nail edge but it can, rarely, present as a bruise or dot shape.
I think there is a very good chance that it's not melanoma, especially due to your young age. However, I would monitor your nail over the next few weeks. Take a photo of it today & then again in 2 weeks, 4 weeks and 6 weeks time & see if it has got bigger, smaller or if it appears to be growing out with the nail. It takes quite a while for nails to grow so you need to leave it about 6 weeks to know if it's growing out. If it appears to be growing out or getting smaller in size it's not melanoma. If you can't wait that long I suggest you see your GP who may prescribe a fungal nail treatment if they think that is the cause. If the treatment doesn't work, see your GP again.
I hope this helps. Good luck & please let us know how you get on,
