Why Is My Toenail Falling Off? Causes and What to Do

Why is your toenail falling off? Most of the time the culprit is an injury — a stubbed toe, something dropped on the foot, or the steady pounding of running and tight shoes. That trauma pools blood under the nail and loosens it from the skin beneath, so weeks later the nail lifts and drops off. Fungal infections and a few other conditions can do it too. The good news is a lost toenail usually grows back; the important part is knowing the cause, caring for the toe safely, and recognizing the few situations that need a podiatrist.

How a Toenail Stays Attached — and Comes Off

A toenail stays put because the hard nail plate is anchored to the nail bed underneath. Anything that breaks that bond can eventually send the nail off. The classic example is a subungual hematoma — blood trapped between the nail and the bed after an injury. The pressure and the pooled blood separate the plate from the bed; as the nail keeps growing forward, the loosened part travels out and, over several weeks, detaches. It often looks dark or black first, which is why an injured nail is sometimes called a “black toenail.”

Common Causes of a Toenail Falling Off

• Injury (most common). A single hard stub or a dropped object — or repeated pressure from running, hiking, or shoes that are too short (“runner’s toe”). This is the usual reason an otherwise healthy nail comes off.
• Fungal infection. A long-standing nail fungus can thicken and loosen the nail until it separates. If that’s the cause, the new nail can get reinfected without treatment.
• Psoriasis. Nail psoriasis can lift and pit the nail and lead to it shedding.
• A whole-body event. A high fever, serious illness, chemotherapy, some medications, or thyroid problems can briefly pause nail growth, leaving a line of weakness (a Beau’s line) that later sheds the nail — often on several toes at once.
• Severe athlete’s foot. A heavy skin infection around the nail can spread and undermine it.

For an overview of the injury type specifically, the American College of Foot and Ankle Surgeons has a helpful page on black toenails. If your nail is thick and discolored rather than injured, our look at how to prevent toenail fungus is a better starting point.

Will My Toenail Grow Back?

Usually, yes. A new nail grows from the matrix — the root tucked under the skin at the base of the nail — and as long as that’s intact, the toenail comes back. It’s slow: toenails grow only about a millimeter a month, so a full toenail can take roughly 12 to 18 months to return, and longer after a bad injury. One honest caveat: if the matrix was badly damaged in a crush injury, the new nail can grow in thicker, ridged, or misshapen — and, rarely, not at all. A toenail coming off repeatedly, or one that won’t grow back, is worth having looked at.

How to Care for a Toenail That’s Falling Off

The main rule is to let it happen on its own. Don’t pull or force off a nail that’s still partly attached — tearing it can bleed, hurt, and open the door to infection. Instead:

• Trim only the loose, snagging edge to keep it from catching on socks.
• Keep the toe clean and dry, and cover it with a light bandage if the nail bed is exposed or tender.
• Wear roomy shoes that don’t press on the toe while it heals.
• Watch for infection — increasing redness, swelling, warmth, pus, or throbbing pain.

A word on blood under the nail: if a dark, painful pocket of blood is building under a freshly injured nail, resist the urge to relieve it yourself by drilling or burning a hole — that’s a job for a clinic, done cleanly, when it’s actually needed.

When to See a Podiatrist

Most cases of a toenail falling off heal fine at home, but some situations deserve a professional look:

• You have diabetes, neuropathy, or poor circulation. Don’t self-treat a detaching toenail — reduced sensation and slower healing turn a small problem into a serious one, so have it checked in person.
• Signs of infection, severe pain, or a large amount of blood trapped under the nail.
• A dark spot or streak that didn’t come from an obvious injury, or one that doesn’t grow out with the nail — that should be examined rather than assumed to be a bruise.
• Toenails that keep falling off, or a nail that won’t grow back.

Because sports and repetitive impact are the most common reason healthy nails come off, an active foot that keeps losing nails is often a footwear or biomechanics issue worth sorting out; you can learn more about our sports podiatry care in Long Beach, or call (562) 426-2551 to have a toe evaluated.