Thick toenails can be caused by a variety of factors, including:

• Aging: The most common cause of thickened toenails is aging. Toenails thicken with age because the growth rate of the nail plate slows.

• Fungal infections: A fungal nail infection called onychomycosis is a common cause of thickened toenails. This infection is caused by dermatophytes, which are nail fungus.

• Physical trauma: An injury to the toe or foot can damage the growth cells that produce keratin, which is what toenails are made of. This can cause the toenail to become thick.

• Psoriasis: Psoriasis is a skin condition that can affect the nails, causing them to thicken and become discolored.

• Other medical conditions: Diabetes and reduced blood flow can impact the healthy function of the toes growth cells, leading to thickened toenails.

Toenails that are thickened are usually painless, but if they get too long, they can become uncomfortable. Proper trimming of thick toenails is important to prevent ingrown toenails and other complications. Before trimming, soak your feet in warm water for 5 to 10 minutes to soften the nails. Then, use nail clippers to make small straight cuts across the toenail, and file the edges with an emery board or nail file to remove sharp edges that could cut your skin. If you suspect a fungal infection, it is important to seek medical treatment to prevent further complications.