Nails serve as protective plates at the tips of our fingers and toes, safeguarding these sensitive areas from injury. Composed primarily of keratin, they are integral to tactile sensation and aid in gripping objects. The nail unit includes the nail plate, the visible hard part, and underlying structures like the nail bed, cuticle, and the nail matrix. If a nail is lost or damaged, it typically regrows.
How Nails Grow
Nail growth originates from the nail matrix, a specialized tissue beneath the skin at the base of the nail, partially visible as the lunula or “half-moon.” This matrix is the source of new nail cells, known as keratinocytes. These cells multiply rapidly, hardening and flattening through keratinization as they are pushed forward. This continuous production forms the visible nail plate.
Fingernails grow faster than toenails. On average, fingernails grow approximately 3.47 millimeters per month, or about 0.1 millimeters daily. In contrast, toenails grow slower, averaging about 1.62 millimeters per month. A lost fingernail may take roughly four to six months to fully regrow, while a toenail can take nine to eighteen months.
Factors Influencing Nail Regrowth
Age is a factor, as nail growth naturally slows down with age due to decreased cell regeneration and reduced circulation. Overall health also affects growth, with conditions like peripheral artery disease potentially slowing it.
Nutritional deficiencies in vital nutrients like protein, biotin, iron, zinc, and vitamins A, C, and E can lead to slower growth or brittle nails. Biotin, a B-vitamin, supports keratin production. Certain medications, including chemotherapy drugs, retinoids, and antibiotics, can temporarily affect the nail matrix, leading to changes like horizontal ridges or slowed growth. Hormonal fluctuations, such as during pregnancy, can also impact nail growth rates.
When Nails Might Not Grow Back
While nails typically regrow, severe and irreparable damage to the nail matrix is the primary reason a nail may not grow back fully. This can occur from deep crushing injuries or other significant trauma that permanently damages the cells responsible for nail production. In such cases, the nail may grow back deformed, discolored, or uneven.
Conditions can also lead to abnormal nail growth or permanent changes. Severe fungal infections (onychomycosis) can cause nails to become thick, discolored, brittle, and misshapen, sometimes resulting in permanent damage or loss. Dermatological conditions like psoriasis or eczema can also affect the nail matrix, leading to changes in nail appearance or growth patterns.
Caring for Your Nails During Regrowth
Good care supports healthy nail regrowth and prevents complications. Maintaining good hygiene is important; keeping the nail bed clean and dry helps prevent infections. Regularly washing and thoroughly drying hands, especially after water contact, is important. Trimming nails straight across can help prevent ingrown nails and encourage proper growth.
Protecting the healing nail and surrounding skin from further injury is also important. This involves avoiding activities that might cause trauma and using protective coverings if needed. Moisturizing nails and cuticles regularly helps prevent dryness and brittleness, promoting flexibility and resilience. Applying antibacterial ointments to damaged areas can aid healing and reduce infection risk.