It’s one thing when you change the nail polish colour on your toenails, but if your toenails naturally change colour, it could indicate a problem brewing behind the nail bed.  

A healthy toenail is usually clear and partially translucent (i.e.: the colour of your skin tone – more or less).  This can change to black, yellow, brown, green or blue, depending on what precisely is going on. If you have a discoloured toenail (also known as “chromonychia”), you can see a foot specialist at our clinic to find out the underlying cause and get the appropriate treatment.

There are many other ways toenail discolouration may present itself, and sometimes the changes may be ambiguous or not immediately obvious. A discoloured toenail may be:

• Red
• Black
• Purple
• Yellow
• Brown
• Green
• Blue
• Yellow-Brown spots
• White streaks
• White on the bottom/pink on top
• White

This list is not exhaustive.

If you notice any changes to the colour, pattern, thickness, shape, texture or consistency of your toenails, it is best to see a chiropodist for guidance.

Why Is My Toenail Discoloured?

The precise colour of a discoloured toenail is a barometer for what is going on behind the nail.  The following is our “colour guide” to discoloured toenails and their causes:

Red/Black/Purple Toenail:  In most cases a black toenail is caused by trauma to the toenail. It may start out as a reddish-purple colour and then gradually change to black. This can be from dropping something on your toe, or repetitive minor traumas such as exercising in shoes that are too small. The black colour typically comes from bruising or blood beneath the nail.  

Yellow/Brown Toenail:  Toenail fungus (also called “onychomycosis”) is the primary cause of yellowing toenails.  Fungus is also one of the most common causes of toenail discolouration.  

Thicker nails can also make your toenails yellow due to the disruption of light passage through the nail.

Green Toenail:  Green nail syndrome (GNS) is a toenail infection caused by bacteria (as opposed to fungus). A bacterial infection is usually confined to a single toenail and often follows some sort of trauma that left an opening in the nailbed, through which bacteria entered.

Blue Toenail:  If you notice a small circular blue mole behind your toenail, it may be something called a blue nevus.  A blue nevus is usually benign and not a cause for concern; however, in very rare cases, it can become cancerous.  If you notice such a discolouration behind your nail, it is best to seek medical attention just to be safe.  

Yellow-Brown Spots:  This can indicate an auto-immune skin-related disease called psoriasis.

White on the bottom half; Pink on the top:  This can indicate kidney problems.

White:  This can indicate liver problems. 

These are just some of the many variations of toenail discolouration.  For more information about the many forms of toenail discolouration and their causes, you can check out this guide:  https://www.webmd.com/skin-problems-and-treatments/ss/slideshow-toenail-color-causes

How Do I Treat Discoloured Toenails?

What Causes Toenail Discolouration?

How Do I Prevent Toenail Discolouration?