Thick Toenails

Written By: Chloe Wilson BSc(Hons) Physiotherapy
Reviewed By: FPE Medical Review Board

What Causes Thick Toenails?

There are a number of different things that can cause thick toenails to develop, some which are more common than others. 

If discoloration is more of a problem than thickening in your toenails, visit the Yellow Toenails section.

1. 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 toenail fungus infections.

Fungal infections 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

What Causes Toenail Fungus?

Thick nail fungus from onychomycosis is usually due to Dermatophytes (most common in temperate western countries), Candida or Non Dermatophytic Molds (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. Thickened toenail fungus infections are typically caused by:

• Nail Injury: damage to the nail allows the fungus to invade and infect the nail
  
• Fungal Foot Infection: a nearby fungal infection e.g. athlete's foot can spread to the nail causing thick toenails
• Poor Foot Hygiene: failing to keep the feet clean and dry
  
• Shoes: tight shoes, or ones that don’t allow your feet to breathe leading them to become hot and sweaty are the ideal breeding ground for fungi
  
• Walking Barefoot: in areas prone to fungal infection such as swimming pools, public showers and gyms
  
• Aging: infections most commonly affect people over the age of 60 as nails naturally thicken and grow slower, the blood supply diminishes and there is increased susceptibility to infection
  
• Weakened Immune System: from illness or medication
  
• Health Conditions: such as diabetes, circulatory problems and psoriasis

Thick toe nails from fungus infections can be highly contagious so it is important to take steps to prevent spreading the infection by keeping your feet clean, dry and covered.

2. Nail Psoriasis

Another possible cause of thick toe nails is psoriasis. Psoriasis is a common skin condition that can also affect the nails, leading to thick nails 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

Typical symptoms of thickened toenails caused by Psoriasis include:

Other Causes of Thick Toenails

There are a number of other things that can cause thick toenails such as:

2. Diabetes

Another possible cause of thick toe nails is 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, thickened 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. 

3. Ram’s Horn

Onychogryphosis usually need to be treated by a podiatrist as the nails 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.

4. Toe Injury

Repetitive minor trauma or pressure on the nail can result in thickened 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 nail bed is damaged.

5. Yellow Nail Syndrome

Thick toenails are more common in the older population. As we get older, nails grow slower but this can lead them to thickening due to the piling up of nail cells, known as onychocytes. Repeated pressure on the feet and reduced circulation can also lead to thick toenails in the aging population. 

Thick Toe Nail Treatment

There are lots of different thick nail treatment options:

• Laser Therapy: Using infrared radiation to produce heat which kills the fungi that causes thickened toenails. There are various mini nail fungus laser devices that you can get to use at home that can be really effective
  
  
• Natural Remedies: Tea tree oil is often used to treat fungal nail infections. Many people report finding it beneficial but there is limited research to support its use
  
  
• Systemic Medication: If you have both skin and nail psoriasis you will be given medication that is for the whole body such as methotrexate
  
  
• Phototherapy: UV light can be helpful in treating both skin and nail psoriasis
  
  
• Trimming Thick Nails: It can really help to keep on top of thick toe nails but keeping the trimmed. This can become quite a challenge as the toe nail thickens more, so you may need a special pair of toenail clippers for thick nails
  
  
• Nail Creams: to rub into and around the nail such as corticosteroid cream, vitamin D or anti-metabolites
  
  
• Injections: Corticosteroid injections under the nail can help to treat thick toe nails – these can be more effective than creams and can be done every few months

Recovering From Thick Toenails

Depending on the cause of your thick toenails, recovery can take anywhere from several days to several weeks. The length of recovery will depend on the severity of the issue, how long your nails have been thickening for, the underlying cause and how closely you follow the recommended treatment plan.

Some cases of thick toenails can be left to heal naturally without any treatment, simply by following good foot hygiene methods and keeping your feet clean and dry.

To speed up recovery from thick toenails you should also regularly trim and file your nails, use an anti-fungal solution (if appropriate), and apply moisturizers or oil to keep your toe nails soft. It’s also important to wear comfortable, breathable shoes that fit properly so that you aren't irritating your thick toenails further. 

Your doctor may take a swab from under your nail or a toenail clipping and send it off for analysis to look for any sign of fungal infection before starting you on medication for your thickened toenails.

Prevention

It can take many months for painful, thick toenails from fungal infections to settle, and the recurrence rate is relatively high at between 10-50%. This makes prevention all the more important. Things you can do help reduce the risk of developing thickened toenails from fungal infections include:

• Good Foot Hygiene: Keep feet clean and dry, and keep nails trimmed 
  
• Appropriate Footwear: Wear clean, cotton socks and good-fitting shoes that allow your feet to breathe
  
• Avoid Going Barefoot: In public areas such as showers and swimming pools
  
• Don’t Share: Use your own towels, footwear and nail clippers/scissors so as to prevent the spread of infections – if visiting a salon for a pedicure, ensure that all equipment is sterilised between uses

Psoriasis is not contagious so you don’t need to worry about passing on an infection from thick toenails if they are caused by psoriasis, unless there is an accompanying fungal infection. 

Thick Toe Nails Summary

There are lots of possible causes of thick toe nails but the most common by far is a fungal infection.

Thickened tonails may be accompanied by thick skin under the nail or around it and the nails may also start to discolor, typically turning yellow.

Thick nails can usually be treated with a variety of nail care routines. You should start by using a manicure tool to gently trim your nails and then apply a moisturizer or oil to soften them. You can also apply over-the-counter antifungal solutions or home treatments such as apple cider vinegar or tea tree oil. If you are still having issues with your thick toenails, you may need to visit your doctor for additional diagnosis.

You may also be interested in the following articles:

• Toe Pain Causes & Treatment
• Yellow Toenails
• Toe Lumps
• Pain On Top Of Foot
• Foot Arch Pain
• Swollen Feet & Ankles
• Foot Numbness
• Why Are My Feet Red?

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Page Last Updated: 23rd January, 2025
Next Review Due: 23rd January, 2027