Arachnodactyly (also known as "spider fingers"). This is a condition where a person's fingers and toes are abnormally long and slender, especially when compared to the palm of the hand and arch of the foot. People can be born with this condition or even develop it later on in life. Some people with "spider fingers" don't have any underlying health issues. Unfortunately, this condition is linked to certain other conditions, such as Mafan syndrome which makes people have long arms, legs, fingers, and toes, flexible joints and scoliosis, and have heart problems.