When it comes to toenail anatomy, a lot can change the structure and growth pattern of your toenails. Case in point: curly toenails. They don’t look quite right and, the truth is, there are several potential causes behind their development. Sometimes it can be an underlying health condition wreaking havoc on your nails, and other times it may be a more direct toenail condition. It’s also wise to ensure curling toenails don’t co-exist with/turn into ingrown toenails, which may become infected.
Let’s take a look at what might be causing your curling toenails, and what you can do about it!
Causes of Curly Toenails

Onychomycosis
This is a fungal toenail infection in the nail unit (the nail plate, surrounding soft tissues and nail folds). It usually results in nail thickening and the formation of pincer nails (curly toenails). Diabetes patients in particular should be on the lookout for diabetes-related onychomycosis, or “ram horn,” and other severe abnormalities caused by toenail thickening and curling.
Autoimmune Illnesses and Deficiencies
Lupus, psoriasis, psoriatic arthritis and thyroid disorders can all cause thickened toenails that eventually degrade and curl. Severe iron deficiency can also cause curly toenails since iron is so critical for maintaining our nail and foot health.
Ill-Fitting Footwear
Perhaps the least serious cause of curly toenails is also the most avoidable — simply neglecting foot care and failing to buy shoes that fit well. Wearing shoes that are far too tight for years (perhaps because you’re procrastinating a proper shoe fitting) is a mistake. When you wear shoes with minimal space in the toe box, the shoe will squeeze both sides of the toe, disrupting normal nail growth and bending the nail root or matrix.

Medications
Drug-induced nail disease is a very real concern for those taking necessary medicines. Some examples of medications that cause curly toenails and other nail growth disruptions include antibiotics, chemotherapy drugs, lithium, and Retinoids.
Genetics
Sometimes your gene pool is responsible for your curly toenails. Your mom and dad can pass down hereditary characteristics like the shape and thickness of your toenails, as well as how much skin you have surrounding the toenails. But don’t worry if you feel like you have no control over genetic traits – proper foot care can still help you manage curly toenails.

Here are some of the best treatments for curly toenails:
- Medical Pedicures: Chiropodists can properly clean and trim the nails to promote healthy growth.
- Antifungal Medicines: These can help with onychomycosis.
- OnyFix: Modern, non-invasive treatment that involves using a special paste to correct nail growth.
- At-home foot care: Remember to keep your feet and nails clean, but don’t try to trim them on your own if they’re severely curled or ingrown. If your toenails become severely curled or ingrown, it’s best to contact a chiropodist.
