What causes finger nails to turn downward?

Just as our eyes do, nails can tell a doctor a lot about the overall health of their patient. Curved nails are caused by: * Insufficient Vitamin B12 * It can indicate Cardiopulmonary disease or asthma * It MAY indicate heart, liver or arsenic poisoning It is probably insufficient Vitamin B12. If you are letting your nails grow very long they also can sometimes grow under or even twist if they are super long.
Just as our eyes do, nails can tell a doctor a lot about the overall health of their patient. Curved nails are caused by: * Insufficient Vitamin B12 * It can indicate Cardiopulmonary disease or asthma * It MAY indicate heart, liver or arsenic poisoning It is probably insufficient Vitamin B12. If you are letting your nails grow very long they also can sometimes grow under or even twist if they are super long.