My Mother Is 76 Years Old And Is Somewhat Bedridden.

My mother is 76 years old and is somewhat bedridden. She has developed some black material on her toenails that can be cleaned off, but I don't know what it is. It is mostly around the cuticle area. There is one place that feels like a scab under her big toe, but there is no reason for there to be one there. Lastly, her toenails are very thick, with some solid material growing underneath of them, the same color as her toenails. It makes it difficult to trim them , because it gets in the way of the nail.