I get sudden sharp pains in my armpits occasionally and they last about a second or rarely they last to about a minute. what is this happening?

Nerve pain: Sudden,Sharp but fleeting pains like those most often are due to impingement or irritability of nerves probably located in the axillary area(armpits) but muscle or tendon origin cannot be excluded. Are the pains brought on by arm movements or a deep breath? Do you wear too tight blouses or bras? Your physician can examine you to try to localize the cause if symptoms persist or worsen.