Basic knowledge explained simply: ‘The nail’ – structure, function and maintenance

In ancient China, long fingernails were seen as a symbol of wealth and social status: those who wore them were showing that they did not engage in any manual work. Even today, nail art featuring especially long and elaborately decorated fingernails makes a statement – albeit mostly in terms of fashion, creativity and style. Different standards apply to toenails, however: toenails that are too long can cause pain and pressure points, then restricting mobility. Regular and professional maintenance of the toenails is therefore essential.

In podiatry, foot health and beauty, a sound understanding of the nail is of key importance. In this second part of our series, we explain how the nail is structured, what functions it fulfils and how to keep it healthy.

To Part 1: Basic knowledge ‘The foot’

Toenails are less than merely a decorative accessory, but perform important functions: they protect the sensitive toes from injury, deliver stability when walking, running and standing, and, thanks to their slightly curved shape, ensure that pressure is distributed evenly across all the toes. On the hands, nails also play a crucial role in fine motor skills, as they support precise movements such as grasping and feeling objects.

Toenails grow significantly slower than fingernails – a full growth cycle can take up to twelve months. Nail growth proceeds in the matrix, the area directly behind the nail plate. Here, new cells are continuously formed, which gradually push forward. Up to 150 layers of dead keratin particles are put on top of each other like roof tiles, giving the nail its stability.

The toenail includes several components that work closely together to ensure a robust protective function and promote healthy nail growth:

• Nail plate (unguis)
  The visible part of the toenail, including keratinised tissue. Protects the underlying tissue.
• Nail bed (hyponychium)
  Soft, well-perfused tissue on which the protective nail plate rests. The nail bed supports the nail and supplies it with nutrients.
• Nail matrix
  The matrix – also known as the ‘nail root’ – is located hidden at the rear end of the nail. New cells are continuously formed here.
• Lunula (“half-moon”)
  A crescent-shaped, pale area at the nail root – the visible part of the matrix.
• Nail fold and nail ridge
  The nail fold locates on both sides of the nail and protects it from external influences. The nail fold delivers a clear demarcation between the nail and the skin.
• Cuticle (eponychium)
  A thin layer of skin at the matrix that protects the nail from the ingress of bacteria and fungi and seals the nail fold.

Ingrown toenail (Unguis incarnatus)

• Symptoms: The nail, which has grown into the surrounding skin, causes painful inflammation and swelling, and may even lead to the formation of granulation tissue.
• Cause: Wearing shoes that are too tight, incorrect nail cutting or a genetic predisposition.
• Treatment: Podiatrists can relieve acute health problems and guide nail growth back onto the correct path thanks to dressings or special techniques such as fitting a nail correction brace.

Nail fungus (onychomycosis)

• Symptoms: White to yellowish-brown discolouration, callus, thickening and brittleness of the nail.
• Cause: Fungal infections, which spread especially frequently in warm, damp environments.
• Treatment: Thanks to professional, long-term therapy, podiatrists can effectively combat a fungal infection and prevent it from spreading.

Injuries and trauma

• Symptoms: Bruising under the nail plate, pain, discolouration of the nail, and in severe cases, detachment of the nail.
• Cause: Contusions, impacts, blows or repeated strain, for example thanks to pressure.
• Treatment: Nail trepanation by a doctor in cases of severe pain and pressure, complete or partial removal of the nail, nail reconstruction.

Brittle, dry and splitting nails

• Symptoms: The toenails become brittle, split or tear.
• Cause: Triggers can include entirely different factors, such as malnutrition, ill-fitting footwear or frequent contact with cleaning products, soap, nail polish and nail varnish remover.
• Treatment: Targeted and regular nail care using moisturising oils and creams, a balanced diet and wearing well-suitable shoes.

Healthy nails are an important part of foot health and play a key role in our general well-being. Understanding their structure and functions helps one appreciate why careful care and timely treatment of any problems are so crucial. Whether for prevention or to address existing health problems, expert support from podiatrists and foot care professionals delivers the care needed to maintain toenails so that they not only look well-groomed but also reliably fulfil their protective and supportive functions.