Why are your Toenails Discoloured?

By Yejide Gbenga-Ogundare

Normally, healthy toenails have a clear and partially translucent color, an indication of a healthy body. And often, one of the first symptoms of an underlying illness is discolored nails. Toenail discolouration, also known as chromonychia is caused by many factors ranging from minor injuries to potentially serious health conditions and this discolouration can appear yellow, green, blue, purple or black.

The most frequent reason for discoloured toenails is nail fungus, which is challenging to treat but rarely a serious source of discomfort and common causes of yellow toenails, include excessive nail polish use. It is, however, possible for the toenails to turn a shade of yellow. This can happen for several different reasons and aside from injuries, most conditions that cause toenails to change color may require treatment from a doctor

Causes of toenail discolouration include nail fungus or onychomycosis which can make nails become yellow, reddish brown, green, or black. If left untreated, the infection will spread and the discoloured area will get wider.

Other common causes of nail fungus include sweaty and damp feet, walking barefoot, cuts or scraps near the nail, and improper foot hygiene. Others include injuries which cause trauma to the nail like stubbing the foot or dropping heavy objects on it which cause a subungual hematoma and leads to a red or purple discolouration.

Also, tight-fitting shoes can stop blood circulation to the toes resulting in discolouration as nails will become bruised and purple while nail discolouration can occur as a result of an underlying health conditions like psoriasis which can manifest yellow-brown spots under the nail, cirrhosis can cause severe whiteness of nails and yellow can signal diabetes.

Nail polish is one of the biggest culprits in regard to toenail discolouration. It contains chemicals like formalin, dimethylurea, or glyoxal that penetrate and stain the layers of keratin in your nail and toenails can get discoloured due to some kinds of medication; chemotherapy drugs cause darkening or white bands across the nail, rheumatoid arthritis drugs may cause a dark brown discolouration, antimalarial drugs cause toenails to turn blackish blue, minocycline can give it a bluish gray tinge, and tetracycline antibiotics can cause yellow nails.

Also, if toenails come into contact with a harmful fungus, this can lead to a fungal nail infection called onychomycosis which can affect any part of the toenail and may cause it to appear yellow. The infection can also be uncomfortable and make it difficult for a person to walk.

Another factor is what is known as yellow nail syndrome, a very rare condition that can cause both fingernails and toenails to turn yellow and make nails grow more slowly, lack a cuticle and damage easily. This has more severe symptoms, including respiratory problems and swelling of the lower limbs but the cause of the condition is unknown, though it is more common in people aged over 50.

If excessive nail polish use is not seen as a likely cause, person with yellow toenails should consider seeing a doctor as they may need a prescription to treat the condition especially if you experience other symptoms like pain, bleeding, changes to the shape or thickness of the nail plate or swelling alongside yellow toenails.