Be careful if red crescents appear on your nails! American study: May be related to systemic diseases such as heart failure and liver cirrhosis

The picture shows a red lunula, with a clear red area visible at the base of the nail; related abnormalities have been documented in medical cases since 1954.

Most of the nails usually show white "crescents". If they appear red, it may be related to internal diseases in the body. A research team from Rutgers New Jersey Medical School in the United States reviewed decades of cases and pointed out that the rare "red lunula" has appeared at the same time as heart failure, cirrhosis, rheumatoid arthritis and other diseases.

The science news website "Science Alert" reported that this study was published in "The American Journal of the Medical Sciences" and was a review of case literature. The research team compiled relevant cases since 1954 and found that red crescents have been associated with cardiovascular, liver, blood, skin and rheumatic immune diseases, but the exact cause of this nail discoloration is still unclear.

The lunula is the exposed portion of the nail root growth area, usually most visible on the thumb. Past cases have shown that in addition to patients with heart failure, liver cirrhosis and rheumatoid arthritis, red crescents have also been seen in cases of systemic lupus erythematosus, alopecia areata and carbon monoxide poisoning.

Multiple nails are more noteworthy. Exclude local lesions on a single nail first.

The research team pointed out that if red crescents appear on multiple nails instead of a single nail, it is more likely to be related to systemic diseases; if only a single nail appears red, local problems such as nail bed infection, subungual bleeding or subungual tumors should be ruled out first.

Research also mentioned that red crescents may be related to the dilation of capillaries under the nails and increased blood flow. When a doctor presses the red crescent during a clinical examination, if the color temporarily turns white, it may support the diagnosis of capillary dilation, but this is only part of the doctor's examination and cannot be used as a basis for people to diagnose diseases by themselves.