Thanks for your query and a picture.
The indentation on your nail is midway and distal.
This indicates that there was some problem 3 to 5 months back. This is so as the growth rate of thumb nail is 6 months.
The probable problem could have been:
-Minor trivial trauma which you may recollect like getting trapped somewhere of a direct hit over nail bed.
- Or suffered from some intestinal issues where the absorption of the micro-nutrients and vitamins was affected, which show changes in the nail/s.
Your Query: Is this normal or could it be a sign of something serious?
This is definitely not a serious matter as the rest of the nail is absolutely healthy, particularly the base corresponding to the last 2 to 3 months.
Hence there is nothing to worry bout at the moment.
Some marks near the nail appear to be signs of nail biting. Do you have the habit of nail biting or stress and anxiety problems which is normal appearance in day-to-day's life?
I hope this answers your query. Please feel free to ask for more or if you need further clarifications or if you feel there is a gap of communication.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.