Horizontal Lines On Your Nails Have A Bigger Meaning Than You Think
If you have noticed lines that appear like grooves or indentations running horizontally across your fingernails or toenails, you may be wondering what's going on. These are known as "Beau's lines."
Beau's lines typically form at the base of the nail, near the cuticle, and move outward toward the tip as the nail continues to grow. Since they move at the same pace as the nail grows, it is possible to determine when the line first formed. Beau's lines can affect one nail or several nails at once, and their depth and prominence may vary.
Although Beau's lines are harmless, they can be an indicator of an underlying health issue. It's important to understand what causes them so you can know whether there is a problem that needs to be addressed.
What causes Beau's lines?
Beau's lines generally occur when there is some sort of extreme stress that has affected your body or an injury has occurred to your nail matrix, the tissue at the base of your nail where new nail cells originate. These can cause nail growth to temporarily slow or halt, creating a visible depression or groove. This interruption typically affects all the nails that were actively growing during the period of disturbance.
According to a 2022 article in Annals of Medicine, when you develop Beau's lines, it means there was a systemic event significant enough for the body to divert its resources away from normal nail growth. However, Beau's lines don't show up right away. It takes several weeks for the nails to grow enough for the area of interrupted nail growth to become visible.
The depth and width of the groove can give clues about the severity and duration of the disruption. In some cases, the interruption may be mild and barely noticeable, while in others, the line may be deeply etched and span the width of the nail plate.
What can Beau's lines tell you about your health?
Our nails change as we age, which can lead to Beau's lines. However, they most often result from severe illness, trauma, nutritional deficiencies, or certain medications. Causes can also include serious systemic diseases such as uncontrolled diabetes, kidney disease, autoimmune conditions like lupus and psoriasis, and severe infections such as pneumonia, typhoid fever, or scarlet fever. Physical trauma to the nail bed — from injury, burns, or repetitive damage — can also lead to Beau's lines. Chemotherapy drugs are another notable cause of Beau's lines on your nails, as they impair the rapidly dividing cells responsible for nail growth. Nutritional deficiencies, particularly in zinc, iron, and biotin, have also been linked to the development of these nail abnormalities. Beau's lines may also be associated with chronic conditions such as hypothyroidism, heart disease, and gastrointestinal disorders that affect nutrient absorption. They can additionally appear following major physiological stress, including heart attacks.
If you have Beau's lines and can't identify a cause for them, for example, a nail injury or a bout of illness, this may indicate an underlying medical condition requiring evaluation and treatment. Recognizing Beau's lines as a potential clinical marker can help in the early detection of systemic health issues and guide timely medical intervention.
How are Beau's lines diagnosed?
While you may be able to identify the likely cause for your Beau's lines on your own, you may also want to see your doctor to rule out any health conditions or medications that may be putting stress on your body.
Your doctor will examine your nails to look for the telltale appearance of Beau's lines. They may also measure the distance between your cuticle and the Beau's lines to determine how long ago the triggering event occurred. They will also ask you questions about your medical history to determine if there is anything that could account for your Beau's lines within that timeframe, such as an infection. They may also draw blood or take a urine sample to screen for any health conditions that they suspect could be causing your nail symptoms.
How are Beau's lines treated?
If a health issue exists, you will, of course, want to see your physician to get that treated. The good news, however, is Beau's lines themselves are not harmful. They will disappear over time as your nails grow out. You will need to be patient, though.
Per Healthline, Fingernails and toenails grow at different rates, so the time it takes for Beau's lines or any damage to fully grow out can vary. On average, fingernails grow about 3.5 millimeters per month, meaning it can take roughly 4 to 6 months for a fingernail to completely grow out from base to tip. Toenails, however, grow much more slowly — about 1.6 millimeters per month — so it may take 12 to 18 months for a toenail to fully replace itself. Factors like age, overall health, and circulation can affect nail growth speed, so these timeframes may differ slightly from person to person.
In the meantime, if their appearance bothers you, you can make your nails look better cosmetically by using a nail ridge filler and nail polish. Just be careful that you don't use any products that might further damage or weaken your nail.
When to see a doctor about Beau's lines
Your nails can reveal many secrets about your health, so if you spot Beau's lines and you can't pinpoint what is causing them, it's a good idea to get professional advice from a healthcare provider.
Additionally, if you have chronic conditions like diabetes and peripheral artery disease, you should always speak with your doctor if you notice any unusual changes in your nails. It's also a good idea to see a doctor if the lines on your nails are accompanied by symptoms of any medical conditions commonly associated with Beau's lines.
With that said, it's generally not necessary to see a doctor if your Beau's lines are connected to trauma. However, the exception would be if there is extensive damage to your nail. Nail ridges due to aging are also harmless and do not require treatment.