How rare are six fingers and common headache causes
A reader asks about polydactyly and whether extra digits are useful or removed at birth. Polydactyly occurs about once in 500 births, more in some populations, with surgery common in the West. A pitcher with six digits on both hands and feet is cited as a curiosity. The other question notes many headache triggers from coughs to stress, foods, alcohol, and chocolate. Ice cream headaches affect about a third of people, caused by cold stimuli and peaking quickly.