What might a horizontal red line under my fingernail indicate?

Reviewed by Yoshinori Abe, MD

Internal Medicine

A horizontal red line under your fingernail may indicate a splinter hemorrhage, which occurs when tiny blood vessels beneath the nail burst. Common causes include nail trauma, fungal infections, psoriasis, or vitamin deficiencies. In rarer cases, it can signal underlying conditions such as endocarditis, lupus, or vasculitis. Because the cause varies widely, evaluating accompanying symptoms is essential for accurate diagnosis.

If you've noticed a red line under your fingernail, don't guess about what it means. Understanding the possible causes early can help you decide whether home care is enough or if you need to see a doctor. Take a free, instant, online symptom check to get personalized insights based on your specific symptoms and clear guidance on your next steps.

Reviewed for medical accuracy: 07/15/2026

What brings you in today?

Can I treat this myself Do I need to see a doctor Where should I go for care I'm concerned about a symptom Concerned about a possible condition My symptoms are getting worse Seeking a second opinion

Not seeing your question? No worries.

Submit your own Question

Explanation

A horizontal red line under the fingernail might be a sign of a nail condition. In some cases, it could be related to underlying health issues or be a benign occurrence.

Nail Conditions: Horizontal red lines, also known as splinter hemorrhages, can sometimes appear due to trauma or minor injuries to the nail. They might also be associated with certain medical conditions, but this is not always the case.
Other Considerations: It is important to observe if there are additional symptoms or changes in the nails or health. If you notice multiple lines, changes in nail color, or any other symptoms, it is advisable to consult a healthcare professional.

Always seek advice from a healthcare provider for a proper diagnosis and to rule out any potential underlying health issues. You can also start by using a free AI symptom checker to help identify what might be causing your symptoms.

(References)

Chang C, Beutler BD, & Cohen PR. (2017). Report of a Patient with Multiple Horizontal Red Bands .... Dermatology and therapy, 28260214.
Oanță A, Iliescu V, & Țărean S. (2017). Half and Half Nails in a Healthy Person. Acta dermatovenerologica Croatica : ADC, 30064606.
Siragusa M, Schepis C, Cosentino FI, Spada RS, Toscano G, & Ferri R. (2001). Nail pathology in patients with hemiplegia. The British journal of dermatology, 11260014.

Thinking about asking ChatGPT?Ask me instead

Tell your friends about us.

We would love to help them too.

For First Time Users

What is Ubie’s Doctor’s Note?

We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.

Was this page helpful?

Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.