I recently lost my big toenail. I googled it, and found two causes, fungal or toe trauma. Neither of those apply to me. Has anybody had a toenail loss for no apparent reason, and how long before I should expect full growth?
I have lost a big toe nail twice, each time due to trauma. I was told it takes about a year to fully grow back, which was accurate.
I wonder if the cause of your loss is worth investigating and don’t know if cause could impact the re-growth time-frame or process. All the best!
Can’t speak to why you’d lose them. I used to lose them due to trauma. shudders
However, it takes over a year to completely grow back 
I think you should go to the dermatologist or podiatrist. either one can let you know if you have a fungal infection and treat it if needed. if you do have a fungal infection losing the nail does not mean the problem is solved.
Fungal infections of the toenail never get solved.
Trust me on this one.
My husband used to lose his big toenails every fall when basketball season started - turned out his socks and shoes were too tight. Bought him shoes with a wider toe box and larger socks and he never lost another nail. Trauma can mean a lot of things.
I periodically lose the big toenail on my right foot, for apparently no particular reason. I think it has to do with running, and pressing against the toe box. I use wide toe box shoes, but it still doesn’t seem to help. That toenail has been partially discolored for over ten years, and grows back that way too. My podiatrist seems to think it’s trivial, so I just wear toe polish to cover it.
I have lost them due to running occasionally.
@busdriver11 - Have you had a dermatologist look at your toenail? The only reason I ask is that mine told me to not have them painted when scheduling my yearly checkup. She said that certain discolorations maybe a sign of cancer.
It might look like this.
http://www.patienthelp.org/diseases-conditions/subungual-melanoma.html
Agree with the the idea that the trauma doesn’t have to be of the traumatic kind to make a toenail give it up. Shoes that might be fine for flatland can be too tight/short for up and down slopes. Low grade ache was the preview for losing a couple of mine.
Admitting to nail fungus is a new personal low, but… I had one verifiable case on one toe. Clipped the nail all the way back to whatever quick remained… all of it. Band-Aids w/ tea tree oil applied daily. Continued clipping off of anything that wasn’t anchored and tea tree oil.
Took a little over a month but it disappeared and hasn’t come back in 4 years.
This certainly limits what kind of shoe I will be able to wear at D’s May wedding.
Thanks for asking, @MichiganGeorgia. I’ll look into it, but the podiatrist sounded awfully sure it’s just a mild case of toe fungus. Half the nail discolored, hasn’t changed in over a decade.
Wait, admitting to nail fungus is a new personal low? Dang cat, you must be one classy guy, cuz that doesn’t even measure on my scale of lowbrow kind of admissions… 
I’ll give it a try. Nothing else works, and it’s not worth taking all those medications that could damage your liver, just for a little discoloring. Hey, if it grows back, just start getting pedicures and bright red nail polish!
Someone I know had success with Penlac. It is a prescription-only antifungal nail polish… not usually covered by insurance. $200 out of pocket vs. taking an oral anti-fungal and monitoring liver function? The choice was easy.
Jeez, much better! Hmm, wonder if they have bright red… 
I tried the oral medication. It required monthly blood tests, I had the side effect of it affecting my taste, and it didn’t work. Other than that, it was great.
Penlac? Tea tree oil? What the hell. I’ll try them. However, after 36 years of having this danged thing, I’m not optimistic.
@MichiganGeorgia Thank you for the link. A sing dark streak showed up a few months ago on my left thumb. I wondering how to get rid of it. Do you go to dermatologist to show your finger nails?
@iglooo - I just go once a year and she checks everything including my finger nails and toe nails… I’m not sure what to tell you except if it’s not growing out or going away I would have it looked at.
@Iglooo - My derm looks at all my finger and toenails. Dark streaks can mean several things. One of them is cancer – but it could also be trauma related.
igloo you may have splinter hemorrhages . you should go to a dermatologist , dermatology covers the following areas of the body
"Dermatologists are specially trained doctors who diagnose and treat conditions of the skin, hair, nails and mucous membranes (such as those lining the eyelids, mouth and nose). "