Nails that always grow with a split in it is almost always because they were damaged at some point. For instance, you might drop a can of peas on your foot, it can damage the matrix (where your nail grows from) and it will never grow properly again. You might not even remember doing it because it didn't seem like a big deal at the time.
Keep the nail as short as possible. If its causing you problems, like pain or irritation you could go to a doctor but their answer would probably be removing part of the nail.
If it isn't really bother you, it isn't all that big a deal, try to live with it.WHY does my big toe nail grow with splits in it?
Split Nails, Prevention and Treatment of Splitting Fingernails and Toenails
If you suffer from split nails (fingernails or toenails or both), then you have come to the right place for therapeutic treatment advice and support.
Note: The information on this site is non-medical. Splitting nails can sometimes be a syptom of disease. Consult qualified medical personnel for medical advice.
As our skin gets dryer due to weather or natural aging, our fingernails and toenails tend to split more often. The medical term for this is onychoschizia, and the splitting can happen because the nail plates are brittle, soft, thin, frail or have ridges. Women suffer more than men from broken, cracked nails, perhaps because the most common cause of splitting nails is soaking in water (often associated with dishwashing). Another cause of split fingernails is fingernail polish remover. Fingernails can also be damaged by accidentally hitting them. To avoid split nails, you shoule avoid the things that cause them:
Wear rubber gloves when washing dishes.
Don't let solvents like paint thinner and overn cleaner contact your nails.
Avoid long tub baths.
Apply lanolin or jojoba lotions to the nails before and after exposure to water.
Avoid damaging your nails...easier said than done, of course, but don't use your nails for prying or pushing any more than necessary.
Here are recommendations for preventing and treating split nails:
Short nails are less likely to suffer damage than long nails.
Wear gloves when performing tasks that may damage the nails.
Wear nail polish, including nail polish with fibers that strengthen the nails.
Use wooden instruments, rather than metal, to push back the cuticle.
Keep nail tips rounded to a smooth curve.
Some supplements, including gelatin, certain vitamins and minerals may help nails grow faster and stronger.