Toenail fungus often starts with mild nail discoloration or lifting. Though it’s not usually serious, the nails may thicken, become brittle, or fall off without treatment.

Nail fungus (onychomycosis) is fairly common.

It usually isn’t a significant concern — it may happen to just about everyone. But when it overgrows, an infection can occur.

Here’s what to know about the stages of toenail fungus and how to treat it before it worsens.

Nail fungus may happen on the fingernails or toenails, though it’s more common on the toes. People with fungal toenail infections often have an infection like athlete’s foot (tinea pedis) or ringworm between the toes.

The earliest stage of toenail fungus typically involves:

  • slight yellow, whitish, or brownish nail discoloration
  • subtle nail bed lifting
  • some mild nail thickening

In the moderate stage, you might notice:

  • more intense nail discoloration and thickening
  • brittle or crumbly nails
  • mild pain or discomfort

When it’s advanced, you may have:

  • severe nail thickening, discoloration, and structural changes
  • nail crumbling
  • nearly complete nail detachment from the nail bed
  • chronic pain or difficulty walking

A chronic health concern can cause:

  • complete nail detachment and damage
  • severe pain
  • a lower likelihood of nail regrowth
  • a higher chance of infection spread to surrounding nails

Keep in mind that people may mistake nail psoriasis for nail fungus. But nail psoriasis typically has a pink, reddish, or purplish tone.

Rarely, people may mistake melanoma for nail fungus. Though melanoma may be difficult to detect, the nails may have more extreme pigmentation changes, such as brown or black color bands on the nail. Speaking with a doctor is a good idea if you have melanoma concerns.

Treating the fungus as soon as possible prevents it from growing and destroying your nail. The timeline of the fungal progression typically looks like this:

  • The early stage typically occurs for about 4–6 weeks.
  • The moderate stage often happens for about 2–3 months.
  • The advanced stage usually occurs after the infection persists for at least 6 months.
  • The chronic stage may start after a year.

It may take about 12–18 months before fresh growth fully replaces the damaged nail. When you start to see healthy nail growth from the base of the nail (after treatment), it shows your body has cleared the infection.

Fungus thrives in moist environments. With that in mind, several things may cause or worsen toenail fungus, including:

  • tight-fitting shoes
  • sweaty feet, mainly when confined inside shoes
  • damp socks
  • shared towels, shoes, or nail clippers
  • warm, humid environments
  • limited foot hygiene
  • bare feet in public pools, showers, etc.
  • feet remaining wet after bathing
  • nail polish used on the infection

Other things that may make someone more likely to get fungus include:

  • medical conditions that worsen blood circulation (i.e., diabetes)
  • diseases or medications that weaken the immune system
  • smoking
  • older ages
  • genetic predispositions

Since fungus is usually present on the body, experts typically consider toenail fungus a cosmetic concern in its earliest stages. But as it worsens, it can cause more severe health concerns. For that reason, they recommend treating it as soon as possible.

Medical treatment options for toenail fungus include:

  • antifungal tablets
  • antifungal nail cream
  • nail-softening cream (so you can help scrape off the infection)
  • laser treatment
  • medical removal of the nail (in case of a severe infection)

Several home remedies may be effective for nail fungus, including:

If you have a weakened immune system, it’s a good idea to speak with a healthcare professional about treatment instead of treating it on your own. Also, contact a doctor if the infection is severe or spreads to other nails.

Toenail fungus often starts as subtle nail discoloration or lifting, but it can thicken, become brittle, and cause nail loss without treatment. Detecting it early, practicing foot hygiene, and using antifungal tablets or creams can help stop its progression.

Though common, toenail fungus can become painful. Home remedies like tea tree oil may be effective, but always contact a healthcare professional if it affects your daily activities.