Beau’s lines are transverse depressions or grooves across the nail plate. These horizontal indentations signal a temporary disturbance in nail growth, often indicating an event affected the body weeks or months prior.
What Are Beau’s Lines and Their Causes
Beau’s lines are horizontal ridges or dents across fingernails or toenails. These grooves result from a temporary interruption in nail growth within the nail matrix. The nail matrix, located at the base of the nail beneath the cuticle, produces new nail cells. When cell division in this matrix is temporarily halted or slowed, the nail plate forms with a visible depression as it grows out.
Causes include acute systemic illnesses (e.g., high fevers, severe infections like COVID-19, measles, mumps, pneumonia, strep, or heart attack) that divert body energy from nail production. Major physiological stressors such as surgery, childbirth, or significant emotional stress also trigger their formation.
Certain medications, particularly chemotherapy drugs, disrupt nail growth. Severe nutritional deficiencies, such as lack of zinc or protein, impact nail health. Local trauma to the nail matrix (e.g., dropping a heavy object or certain manicuring practices) may also cause these lines. Chronic conditions like diabetes, hypothyroidism, and peripheral artery disease can interfere with blood flow to the nail matrix, contributing to their appearance.
Managing Beau’s Lines
Addressing Beau’s lines involves identifying and managing their underlying cause. There is no direct “treatment” for the lines themselves; they are a physical record of a past event and will not disappear until the affected nail grows out. If a medical condition is suspected, consult a healthcare professional to diagnose the root cause. Treating the underlying condition can prevent new lines from forming.
If medication is the contributing factor, discuss alternatives or management strategies with a healthcare provider. When trauma is the cause, protect the affected nail from further injury. While waiting for the nail to grow out, supportive nail care helps maintain nail health, including keeping nails trimmed to prevent snagging and moisturizing cuticles for flexibility. Wearing gloves during household chores or other activities protects nails from additional injury.
Outlook and Prevention
Beau’s lines are temporary nail changes that eventually grow out. The time depends on nail growth rate. Fingernails grow about 3.47 millimeters per month, so a Beau’s line on a fingernail grows out in three to six months. Toenails grow slower, averaging 1.62 millimeters per month, taking 12 to 18 months to fully grow out.
Preventing new Beau’s lines involves maintaining overall health and addressing potential triggers. This includes managing chronic medical conditions like diabetes or thyroid disorders. Ensuring adequate nutrition, avoiding deficiencies in zinc and protein, supports healthy nail growth. Protecting nails from significant physical trauma and being mindful of severe physiological or emotional stress can reduce their appearance.
When to Seek Professional Advice
Consult a doctor if the cause of Beau’s lines is unknown or if they appear without an obvious preceding event. A healthcare professional can help determine the underlying reason, as these lines can indicate an undiagnosed health condition.
Also seek medical attention if Beau’s lines are accompanied by other concerning symptoms, such as pain, discoloration, or swelling around the nail. If lines appear on multiple nails without a clear cause, or if there is any doubt about the underlying condition, a medical evaluation provides clarity. A doctor can examine nails, review health history, and recommend appropriate diagnostic tests or management strategies.