Nails support and protect the sensitive tips of our fingers and toes. Fingernails also help us to pick up objects, scratch an itch or untie a knot. Fingernails grow about three times faster than toenails.
Nail problems affect people of all ages. Diet is generally not responsible for abnormal nail changes, unless the person is suffering from severe malnutrition. Some nail conditions need professional treatment from either a doctor or a dermatologist, while others respond to simple self-help techniques and minor lifestyle changes. When in doubt, seek medical advice.
Toenail problems can affect people of all ages, but tend to be more common in older people. Common causes of fingernail problems include injury, infection and skin diseases such as eczema and psoriasis. Causes of toenail problems include trauma, ill-fitting shoes, poor circulation, poor nerve supply and infection. Problems with toenails can be successfully treated by a podiatrist.
Structure of the nail
Nails are made from a protein called keratin. This is the same protein that makes up skin and hair. Nails grow from cells that multiply within the base of the nail, then layer on top of each other and harden. This is called keratinisation.
The strength, thickness and growth rate of nails are characteristics that we inherit from our parents. The structures of the nail include:
- Nail matrix – where nail growth occurs, tucked under the skin behind the nail
- Nail plate – the visible part of the nail
- Nail bed – the nail plate sits on top of the nail bed. The nail plate looks pink because of the blood-rich capillaries in the nail bed
- Lunula – the crescent-moon shape that you can sometimes see at the base of the nail plate
- Nail folds – the slender skin grooves that hold the nail plate in place
- Cuticle – the flap of thin tissue over the base of the nail plate.
There are a number of conditions that can affect our nails, with different causes and treatments.
The healthy nail plate is pink, and the nail looks white as it grows off the nail bed. Causes of discoloured nails typically include:
Lifted nail plate
- Nail polish
- Nicotine from cigarette smoking
- Hair-colouring agents
- Certain infections
- Injury to the nail bed
- Some medications, including antibiotics, anti-malarial medications, and some medications used in chemotherapy
If the nail plate lifts off the nail bed, it will appear white. Common causes include:
- Overzealous cleaning under the fingernails
- Nail polishes that contain hardening chemicals such as formalin
- Rough removal of artificial nails
- Tinea (a fungal infection).
This condition affects the toenails more than the fingernails. Older people are at greater risk. Causes include:
- Fungal infection
- Poor circulation
- Arthritis in the toes
- Altered gait (walking) pattern
- Ill-fitting shoes
Ridges running either the length or width of the nail plate can have a number of causes, including:
- Age-related changes
- Trauma to the nail matrix
- Overzealous attention to the cuticles
- Fever or illness
- Rheumatoid arthritis
- Peripheral vascular disease
- Lichen planus infection.
In this condition, the nail plate splits or layers as it grows off the nail bed. Common causes include:
Deformed or brittle nails
- Having constantly wet hands, especially while using soap and washing detergents
- Frequently using and removing nail polish
- Continuous mild trauma such as habitual finger-tapping or using the nails as tools (to pick between the teeth, for example).
A violent toe-stubbing, dropping a heavy object on the toe or some other trauma can injure the nail bed and cause the nail to grow in a deformed way. The nail may be thickened or ridged. It is a normal ageing process for nails to thicken.
Deformed or brittle toenails can benefit from regular professional attention. Trimming, shaping and nail care from a podiatrist can improve the health of your toenails and help diagnose and treat more serious nail problems.
Bacterial infection of the nail
The Staphylococcus aureus bacterium is a common cause of bacterial infection of the nail. Typically, the infection first takes hold in the fold of skin at the base of the nail (proximal nail fold). Without treatment, the infection can worsen, leading to inflammation and pus. It is often associated with candida infection, particularly when it becomes chronic.
Activities that predispose a person to a bacterial nail infection include:
Inflammation of the skin alongside the nail – paronychia
- Having constantly wet hands
- Overzealous attention to the cuticles
- Severe nail biting, which can expose underlying tissues to infection
- Eczema around the fingernails.
The skin lying alongside the nail can become infected with bacteria, typically Staphylococcus aureus. This infection is called paronychia. Symptoms may include pain, redness and swelling around the cuticle and yellow-green discharge.
Treatment for paronychia includes:
- Keeping your feet as dry as possible
- Use of barrier creams, antiseptic lotions and antifungal preparations
- Antibiotic therapy (in acute cases).
Chronic paronychia (where the condition is present for a long time) is more difficult to treat. In chronic paronychia, the nail may distort and become discoloured, and the skin may lift at the site of infection. Sometimes, the inflammation spreads from one nail to another. A range of micro-organisms working together are responsible for chronic paronychia.
Fungal infections, such as tinea, are spread from one person to another and can affect the fingernails or toenails. Without treatment, the nail bed itself can become infected. People with diabetes or with compromised immune systems are at higher risk of fungal infection.
The characteristics of a fungal nail infection depend on the cause, but may include:
Treatment for fungal infection includes:
- Lifting of the nail plate off the nail bed
- Thickening of the nail plate
- Crumbling of the nail plate
- Discolouration, usually in streaks
- White, yellow or green smelly discharge
- Flaking and pitting of the surface of the nail plate.
Trauma to the nail
- Antifungal preparations applied topically (directly to the nail) or taken orally (by mouth)
- Professional trimming, shaping and care of the toenail by your podiatrist.
A blow to the nail or compulsive nail biting can cause a range of problems, including:
- Bruising of the nail bed
- Lifting of the nail plate
- Loss of the nail plate
- Nail ridges
- Deformed growth of the nail plate, if the nail matrix is injured.
One of the most common problems treated by podiatrists is ingrown toenails. The big toe is particularly prone to this painful condition. Causes may include:
- Incorrect nail-trimming technique
- Trauma (such as stubbing your toe)
- Nails that naturally curve sharply on the sides and dig into the skin
- Wearing tight shoes.
Treatment from a podiatrist depends on the severity of the injury, but may include removing the ingrown nail section using a local anaesthetic.
Suggestions to prevent an ingrown toenail include:
Skin diseases and nails
- Trim your nails straight across rather than rounding off the edges.
- Wear comfortable, well-fitting shoes that don’t press on your toes.
Skin diseases such as psoriasis, eczema (dermatitis), lichen planus or lupus can affect the nails. Abnormalities may include pits, grooves or crumbling nails.
Unusual nail shape
Unusual nail shape – such as the nails becoming concave – can be caused by iron deficiency.
Nails can be affected by tumours
– including squamous cell carcinoma, usually caused by infection with the human papillomavirus (HPV). Melanoma can also affect the nail.
Splinter haemorrhages of the nail
These are thin lines of blood running along the nail bed. Causes include injury, severe anaemia, infective endocarditis (inflammation of the inner tissue of the heart) and certain diseases such as rheumatoid arthritis.