Although there are nail problems that can be resolved with proper care, others, on the other hand, are an indicator of an underlying pathology and may be the first sign of a disease. Fingernails are composed of laminated layers of a protein called keratin and grow from the area at the base of the nail known as the cuticle. Healthy fingernails are smooth, with no indentations or nicks. They are uniform in color and consistency and free from blemishes or discoloration.
Sometimes the nails develop harmless longitudinal ridges that go from the cuticle to the tip of the nail and that become more marked as the years go by. They can also develop white lines or dots due to injuries, but these are defects that usually disappear as the nail grows.
However, there is a whole series of characteristics that can provide clues about global health. From the website of the American Mayo Clinic, they stop at some of them:
1. small depressions: They are common in people with psoriasis, a disorder characterized by scaly lesions on the skin. These tiny pits in the nails may also be associated with connective tissue disorders, such as Reiter’s syndrome, and alopecia areata, an autoimmune disorder that causes hair loss.
2. curved nails: The tips of the fingers seem to lengthen and the nails curve around them, this usually happens with the passing of the years. Sometimes it is the result of low oxygen in the blood and could be a sign of various types of lung disease. It is associated with inflammatory bowel disease, cardiovascular disease, liver disease, and AIDS.
3. Spoon nails or koilonychia: They are soft nails that appear flattened and with cavities. The depression is usually large enough to hold a drop of fluid. Spoon nails are often a sign of iron deficiency anemia or a liver disorder known as hemochromatosis, in which the body absorbs too much iron from the diet. Spoon nails may also be associated with heart disease and hypothyroidism.
4. Terry’s Nails: In this disorder most of the nails appear white except for a narrow pink band at the tip. Terry’s nails can sometimes be attributed to aging. In other cases, they may be a sign of a serious underlying condition, such as liver disease, congestive heart failure, kidney failure, or diabetes.
5. Transverse furrows or lines of Beau: They are slits that cross the nails. They can appear when growth in the area around the cuticle is interrupted by injury or serious illness. Conditions associated with Beau’s lines include uncontrolled diabetes and peripheral vascular disease, as well as diseases associated with high fever, such as scarlet fever, measles, mumps, and pneumonia. Beau’s lines can also be a sign of zinc deficiency.
6. onycholysis: Fingernails become loose and may separate from the nail root. The separated part of the nail becomes dull with a white, yellow or green tint. Sometimes split nails are associated with an injury or infection. In other cases, nail separation is a reaction to a particular drug or consumer product, such as nail hardeners or adhesives. Thyroid disease and psoriasis can also cause nail splitting.
7. yellow nail syndrome: Nails thicken and grow slowly. This results in a yellowing of the nails. Yellow nail syndrome may also be associated with swelling of the hands, known as lymphedema.