What Does It Mean If The Bottom Of My Nail Turns Red?

We’ve written before at HuffPost UK about the surprising things your nails can tell you about your health.

Horizontal ridges, dark lines, and brittle or “spoon-shaped” talons can sometimes reveal conditions like uncontrolled diabetes and anaemia.

But researchers have reviewed another red flag that shows up on the lunulae (those half-moon-shaped white semi-circles at the base of your nails) first.

It “may reflect both systemic disease activity or local pathology such as subungual tumour,” the researchers say, though the cause remains “unclear”.

A review of case studies, published in The American Journal of the Medical Sciences, has suggested that red lunulae could be a sign of various health conditions.

“The lunula, the half-moon-shaped visible portion of the distal matrix most apparent in the thumbs, is typically white in appearance and contributes to the shape of the nail plate. Abnormal coloration of the lunula may signify an underlying disease,” researchers wrote.

While “rare”, they added, red lunulae was first described in the 1950s and has since been spotted in other isolated cases.

When noticed, the symptom has been linked to a broad range of conditions, including:

• rheumatoid arthritis,
• liver cirrhosis,
• heart failure,
• alopecia areata (an autoimmune condition leading to patchy hair loss),
• lupus,
• dermatomyositis (a rare autoimmune disease linked to weaker muscles and skin rashes),
• lymphoma,
• psoriasis,
• carbon monoxide poisoning,
• twenty-nail dystrophy (a condition affecting all toenails and fingernails, making them appear brittle), and
• lymphogranuloma venereum (an STI caused by strains of chlamydia bacteria).

The researchers said we still don’t know the mechanism behind the symptom. We’ve only found a link and not a cause.

Red lunulae have been associated with heart failure for decades, while other research suggests nail colour changes might be linked to connective tissue disorders too.

The paper reads: “Upon examination, if the clinician decides that a patient meets the criterion for presenting with true red lunulae, a general medical examination should be performed.

“It is important to keep in mind the possible systemic diseases previously seen tied to red lunulae while evaluating the patient.”