Thick, yellow nails are usually caused by the presence of a fungal nail infection. A fungal infection of the toe nails is a common foot problem. Nail fungus (onychomycosis) is an infection of the nail plate and nail bed. It is caused by various types of fungi, which are commonly found throughout the environment. Fungi are simple parasitic plant organisms that do not require sunlight for growth. A group of fungi called dermatophytes have evolved to attack human nails and skin.
The infection of the nail begins with some type of trauma to the nail. The dermatophyte gains entry into the nail and begins to feed on the nail protein called keratin. The big toe nail is the most commonly infected toe nail.
Our big toe nails can get damaged or traumatized from:
The way we walk or run. ( because of a unstable low arched foot or bunion)
The shoes we wear ( tight fitting shoes or high heels)
The type of job (the requirement to use steel-toed safety boots).
Furthermore, the environment inside of a shoe is dark and damp which provides a perfect growing climate for nails and skin fungus. Other contributory factors are a history of athlete's foot (fungal skin infection of the foot) and sweaty feet.
Several research studies have estimated onychomycosis affects 3% to 13% of the population. The vast majority of people who have fungal nails don't even recognize the existence of a problem and therefore don't seek treatment for many years because their thick nails are not yet causing them pain.
The rate of fungal infections rises sharply among older adults above 65 years as they start to experience more medical problems. For instance, those who suffer chronic diseases, such as diabetes, circulatory problems, or immune-deficiency conditions, are especially prone to fungal nails. This can result in fungal nails being considered a minor problem in comparison to other concurrent medical problems.
Fungal infections of the nail can be graded as mild, moderate or severe. The severe fungal nail infection occurs when the infection extends into the nail matrix (the area of the nail at the base which has white half-moon). A severe fungal nail infection is very difficult to treat and has a poor prognosis.
Fungal nails can be treated by:
Thinning the nail plate
Removing diseased nail and fungal debris back to healthy appearing nail.
Applying topical nail softeners and topical anti-fungal medication exposed nail bed and remaining nail plate
Application of laser to nail plate
Oral anti-fungal medication
If you suspect you have a fungal nail infection you should visit a chiropodist/podiatrist to confirm if you have a fungal nail infection and discuss your treatment options.