Do Your Fingernails Grow Faster on Your Dominant Hand?

Research has shown the smallest finger's nail grows the slowest ¹ while the middle finger's nail grows the fastest. ²

Your fingernails grow faster during the summer than in the winter.²

One theory for this is that since higher temperatures (generally associated with summer) cause blood vessels to expand³, there is better blood circulation and thus, more blood flow and nutrients going to the nails allowing for nails to grow faster in warmer temperatures. When blood circulation worsens, such as with some illnesses, the same concept applies such that nail growth will decrease.⁴

Males' nails tend to grow more rapidly than females'; however, during pregnancy, females' nails grow faster because of increased hormones (estrogen and progesterone) in the body. Same goes with during puberty; during this time, hormone levels are higher and thus nail growth also speeds up. ²