Why Toenails Turn Yellow or Thick: Common Causes
Toenails that turn yellow, thicken or crumble are common, especially with age. A fungal infection is one possible cause, but it isn't the only one. Knowing the possibilities helps you choose the right next step.
Fungal nail infection
A fungal infection of the nail, known medically as onychomycosis, is a common cause of thick, yellow-brown or crumbly toenails. It often starts at the tip or edge of the nail and spreads slowly. It is more likely if you've had athlete's foot, your feet are often damp, you use shared showers or you're older. A doctor can confirm it by testing a small sample of the nail, which matters because several other conditions look similar.
Pressure and injury
Repeated pressure from tight or pointed shoes, running, or a single injury such as stubbing a toe can thicken a nail and change its color. Bleeding under the nail turns it dark red, purple or black and grows out over months.
Ageing and circulation
Toenails naturally grow more slowly and tend to thicken with age. Reduced blood flow to the feet can add to this, and anyone with circulation problems or diabetes should have nail changes checked rather than managing them alone.
Skin conditions
Psoriasis can cause pitting, thickening, discoloration and separation of the nail, and is easy to confuse with a fungal problem. Other skin conditions can affect nails too.
Nail polish and lifestyle
Dark polish worn without a base coat can stain nails yellow, and smoking can discolor fingernails. These changes usually fade as the nail grows out once the cause stops.
What to do next
Because the causes vary, the first step for a persistent change is the right diagnosis, especially if a nail is painful, lifting off or spreading to other nails. Alongside that, good foot hygiene helps whatever the cause. If you choose a cosmetic routine such as Nails Clean Pro, treat it as part of everyday care, not a substitute for medical advice. See when to see a doctor.
About Nails Clean Pro
A twice-daily topical spray for nails and the skin around them, sold in 2, 3 and 6-bottle packs with a 60-day money-back guarantee from the seller.