What Causes Horizontal Indentations And Splinter Hemorrhages In Nails?

I seem to have some issues going on with my nails. First I have horizontal dents in a few of my nails. Blood work was done and everything came back negative except I had a low positive ANA. Now I noticed I have splinter Hemorrhages in more than 1 nail. I ve had them before but didn t pay attention till now since they seem to come again. Not sure if I should be worried?