Do fingernails grow faster than toenails?
Fingernails do indeed grow faster than toenails. In fact, they grow about two to three times faster depending on a person's age, gender, diet, activity, genetic traits, and the season. While it takes about 6 months for a fingernail to replace itself from the root at a rate of about 3 millimeters per month, toenails grow back in 12-18 months at a rate of about 1 millimeter every month (Kids Health).
So why do fingernails grow so much faster than toenails? There are actually two theories that attempt to shed some light on this question. First, it is possible that, because hands are physically closer to the heart than are feet, fingers get better blood circulation and consequently better access to oxygen and nutrients (Allan). Nutrients are transported to the nail through capillaries in the nail bed (shown in the Figure), located directly underneath the hardened nail plate (azTeen Magazine). Second, this disparity could be due to trauma (Allan). Fingernails experience almost constant trauma through tapping, typing, bumping, and other seemingly insignificant actions. These persistent minor traumas stimulate fingernail growth. Toes, on the other hand, are not exposed to nearly as much trauma as they are usually bundled up safely inside socks and shoes. Similarly, fingernails on a person's right hand grow faster in right-handed people than on their left hand and vice-versa (Campbell and Reece).
Nonetheless, fingernails and toenails both grow the same way. The main component of nails is a protein called keratin, which can also be found in skin, hair, horns, and hoofs (Campbell and Reece). Nail growth is actually caused by pressure in the nail matrix near the base of the nail since the new nail cells at the root of the nail push out the old nail cells (Forester). Then, these old nail cells harden and flatten so that they slide along the nail bed as more new cells are made (MedicineNet.com). The growth of these cells depends largely on finger length (longer fingers have faster growth rates), nutrition (extreme dieting and low protein intakes slow nail growth), age (people under the age of thirty have greater nail growth), and season (nails grow fastest during the summer) (azTeen Magazine).