Nails that curve downward, a condition known as nail clubbing, indicate that there could be an underlying health condition. Most often, these issues involve diseases of the lung and cardiovascular system. Nail clubbing m... More »

Fingernails can grow downward as a result of a condition called nail clubbing in which the fingers grow larger, while the nails grow around and curve over the larger fingertips, explains Mayo Clinic. Health problems such... More »

Fingernails can grow downward as a result of a condition called nail clubbing in which the fingers grow larger, while the nails grow around and curve over the larger fingertips, explains Mayo Clinic. Health problems such... More »

According to the Toronto Star, fingernails that curve downward are sometimes called clubbed nails, a condition which is either congenital or a symptom of a developing condition, such as respiratory disease. Wikipedia not... More »

When black lines occur vertically in the nail, they are called longitudinal melanonychia, which is a condition caused by an overproduction of melanin. Similar to moles found on the skin, these lines are no cause for conc... More »

According to Dr. Standley, flat nails can indicate Raynaud's Disease, a condition characterized by cold fingers and toes. Flat nails can also be caused by an iron, protein or vitamin B12 deficiency, psoriasis or diabetes... More »

Dented fingernails are usually caused by an underlying health conditions, such as psoriasis, eczema, alopecia areata and Reiter Syndrome. These diseases affect the growth of the nail in the nail matrix or cause a loss of... More »