Caused by enlargement in connective tissue as compensation for a chronic lack of oxygen. Lung disease is present in 80 percent of people who have clubbed fingers. Also may appear in heart disease or cancer. Look for an arc of brownish discoloration. May appear in a small percentage of people who have kidney failure.
Arsenic poisoning is the cause.
The nail separates from the nail bed. Pitting Small pits or depressions. Most common nail problem seen in 25 percent to 50 percent of people with psoriasis. Spoon nails Soft nails that look scooped out. Depression is usually large enough to hold a drop of liquid.