If you’re noticing a finger nail with red lines (streaks), it can have several causes—some harmless, others worth checking.
🔍 Most common cause
1. Splinter hemorrhages
- Thin red or brown vertical lines under the nail
- Look like tiny splinters
- Usually caused by:
- Minor trauma (hitting or pressure on the nail)
- Repetitive use of hands
- Often harmless and grow out with the nail
⚠️ Other possible causes
2. Injury or nail damage
- Even small unnoticed bumps can cause red streaks
3. Skin conditions
- Psoriasis or eczema can affect nails and cause lines or discoloration
4. Infections or medical conditions
- Rarely, splinter hemorrhages can be linked to conditions like:
- Infective endocarditis
- Vasculitis (blood vessel inflammation)
👉 These cases usually come with other symptoms (fever, fatigue, illness)
🚨 When to see a doctor
Get it checked if:
- Lines don’t grow out over weeks
- You see many nails affected at once
- You have pain, swelling, or fever
- You didn’t have any injury and they keep appearing
🧠 Important note
- Single or occasional lines → usually minor injury
- Repeated or multiple nails → worth medical evaluation
🧠 Bottom line
Red lines in nails are often harmless, but persistent or unexplained cases should not be ignored.
If you want, you can describe how the lines look (thin, wide, one nail or many), and I’ll help you narrow it down more precisely.
