1. First of all the nail is like a small visualizer, many diseases in the human body can be reflected from the nail. Healthy people's nails are glossy, smooth, translucent, uniformly light red, with a certain curvature attached to the end of the finger. In its root there is a half-moon white nail arc, the nails play a protective role, commonly known as the "circle of health", the shape of the nails, gloss, color changes, can reflect the health of the body.
2. Secondly, if the color of the fingernail is purple, it is likely to be cyanosis; it is mostly caused by blood stasis and lack of oxygen. Red blood cells carry oxygen to the body tissues and are usually pink in color. When there is a lack of oxygen in the blood, it appears blue. Cyanosis usually means a problem in the lungs, indicating a blood clot in the lungs; or you have capillary bronchitis, chronic obstructive pulmonary disease, or severe pneumonia; nails can also appear blue when at high altitude.
3. Finally, spoon-shaped nails (also known as concave nails or reverse nails) are characterized by a spoon-shaped depression in the center of the nail plate and thinning of the nails. It either indicates too much iron in the body (hemochromatosis) or too little iron in the body (anemia). Pale nails are a common symptom of anemia. People who are malnourished also have thin, brittle nails. The presence of longitudinal ridges on the nails indicates a possible deficiency of iron, folic acid, and protein.
Cautions
Having dimpled nails is a lack of many nutrients, which can be taken from eggs and garlic, and it is recommended that patients with dimpled nails eat more of them as appropriate. There is also a lot of bad stuff in the ancient I Ching, which says that sunken nails represent a big disaster and can be kicked away.