Thick Toenails

Thick toenails are a common problem, particularly in the elderly population. It can be tempting to ignore them, hoping that they will get better on their own, but they are usually an indication of an underlying problem. 

The two most common causes of thick toenails are a fungal infection or a medical condition known as psoriasis, so we will start by having an in-depth look at both of those, including the symptoms, diagnosis and treatment options for each one.


Fungal Nail Infection

Fungal nail infections are the most common cause of thick toenails, accounting for almost half of all nail-related problems. Around 10% of the population of the States suffer from fungal nail infections. They typically affect the toenails but can in some instances affect the fingernails as well. The medical term for a fungal nail infection is onychomycosis or tinea unguium.

Fungal Nail Symptoms

Fungal nail infections are a common cause of thick toenails

The infection usually develops first on the edge of the nail and gradually spreads to the middle. The nail gradually thickens and may become discoloured, usually yellow, white, brown or black.

The thick toenails become more brittle as they thickens and small pieces may crumble or break off. As the condition gets worse, pain and swelling may develop in the skin underneath and around the nail. The nail may lift up from the nail bed and there may be an unpleasant odour due to the infection.

Causes of Fungal Nail Infection

Thick toenails from onychomycosis are usually due to Dermatophytes (most common in temperate western countries), Candida or Non Dermatophytic Moulds (most commonly affecting people who live in hot, humid climates).

It is normal to have microscopic fungi on your skin but sometimes this can lead to infection. Factors that increase the risk of developing fungal infections include:

1) Nail Injury: damage to the nail allows the fungus to invade and infect the nail

2) Poor Foot Hygiene: failing to keep the feet clean and dry


4) Walking Barefoot: in areas prone to fungal infection such as swimming pools, public showers and gyms


6) Weakened Immune System: from illness or medication

7) Health Conditions: such as diabetes, circulatory problems and psoriasis


Treatment Options




2) Nail Removal: Either done surgically or with chemicals. This gives direct access to the nailbed which aids healing 

3) Laser Therapy: Using infrared radiation to produce heat which kills the fungi that causes thick toenails


Prognosis & Prevention


1) Good Foot Hygiene: Keep feet clean and dry, and keep nails trimmed 

2) Appropriate Footwear: Wear clean, cotton socks and good-fitting shoes that allow your feet to breathe

3) Avoid Going Barefoot: In public areas such as showers and swimming pools


Nail Psoriasis

Psoriasis is a common skin condition that can also affect the nails, leading to thick toenails with areas of pitting, ridging, or abnormal contour. Psoriasis of the nails is accompanied by skin psoriasis in approximately 95% of cases, with the classic feature of patches of red, crusty, flaky skin covered with silvery scales, typically on the elbows, knees and scalp and trunk. Psoriasis is thought to be caused by a problem with the immune system which causes an increase in the production of skin cells.

Symptoms of Nail Psoriasis




3)  Nail Lifting: In some cases, the nail may lift up off, or separate from, the nail bed, starting from the tip and extending towards the root of the nail. This is known as onycholysis

Treatment for Nail Psoriasis


2) Phototherapy: UV light can be helpful in treating both skin and nail psoriasis

3) Nail Creams: to rub into and around the nail such as corticosteroid cream, vitamin D or antimetabolites



Other Causes of Thick Toenails

Let’s have a look at some other possible causes of thick toenails:


1) Yellow Nail Syndrome



2) Aging



3) Paronychia

Paronychia is a nail disease caused by a bacterial infection at the side or base of the nail. It may develop suddenly or gradually. The skin around the nail is usually red, inflamed, hot and painful and there is gradual thickening and discoloration of the nails and pus around the nail. It can affect the fingernails or toenails.

4) Diabetes

Foot problems are common in people with type 2 diabetes due to the poor circulation and nerve damage associated with the condition. The nails do not receive the necessary nutrients to grow properly which can lead to blackened, thick toenails. Good foot care is vital for anyone who suffers from Diabetes and if you notice anything unusual, even if it seems fairly minor, you should seek medical advice immediately. 

5) Ram’s Horn

Ram's horns nails

Ram’s Horn, aka onychogryphosis, is a condition most commonly seen in the elderly, where overgrowth of the toenails leads to discoloured, deformed (typically curved), thickened toenails that gradually curl to resemble a ram’s horn. It typically develops due to cell damage from wearing tight, ill-fitting shoes, decreased blood supply to the nail, trauma/injury (such as dropping something heavy on the foot), infection, poor foot hygiene and failure to regularly trim the toenails.

Onychogryphosis usually need to be treated by a podiatrist as they become too thick to cut with conventional scissors or clippers. The nail may need removing altogether using the chemical phenol or a carbon dioxide laser.

6) Injury

Repetitive minor trauma or pressure on the nail can result in thick toenails. This commonly affects athletes and runners or people who wear tight, ill-fitting shoes. Alternatively, a more major injury, such as stubbing your toe or dropping a heavy object onto the toe can lead to thick toenails, particularly if the nailbed is damaged.

What Next?



Go to Diagnosis Overview or Foot Pain Guide

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