Some health issues that can cause fingernail changes include pulmonary disease, lupus and psoriasis, according to WebMD. Heart disease is also a condition that causes changes in the fingernails, as are diabetes and melanoma.
Fluid in the lungs or low levels of oxygen can impart a bluish tinge to the nails, says WebMD. Anemia can make the nail beds look pale. Iron deficiency thins the nails out and gives them ridges and a peculiar curve. People who suffer from lupus develop blood vessels in the folds of their nails, and psoriasis causes split or rippled nails. People who have thyroid disease also have nails that are brittle and split.
A person with heart disease presents with red nail beds, according to WebMD. People who have liver disease often have white nails, while people with kidney disease have nails that are half white and half pink. Thick, yellow nails that grow slowly are a sign of lung disease. Clubbing of the nails may also be a sign of lung disease or inflammatory bowel disease, claims American Family Physician. If the patient's nails are yellow and somewhat pinkish at the base, he might be diabetic, states WebMD. Melanoma might be the cause of dark lines that show up beneath the nail.